{\rtf1\ansi\ansicpg1250\deff0\deflang1050\deflangfe1050{\fonttbl{\f0\fswiss\fprq2\fcharset238{\*\fname Arial;}Arial CE;}{\f1\froman\fprq2\fcharset238{\*\fname Times New Roman;}Times New Roman CE;}{\f2\fswiss\fprq2\fcharset238 Arial Narrow;}{\f3\froman\fprq2\fcharset161{\*\fname Times New Roman;}Times New Roman Greek;}{\f4\froman\fprq2\fcharset0 Times New Roman;}{\f5\fmodern\fprq1\fcharset238{\*\fname Courier New;}Courier New CE;}}
{\*\generator Msftedit 5.41.15.1507;}\viewkind4\uc1\pard\nowidctlpar\sl-43\slmult0\f0\fs4\par
\pard\nowidctlpar\li19\ri19\sl-187\slmult0\qj\f1\fs20 PERIODICUM BIOLOGORUM Vol. 97, No 1, 55-60,1995\par
\pard\nowidctlpar\li19\ri19\sl-48\slmult0\qj\f0\fs4\par
\pard\nowidctlpar\sl-187\slmult0\qj\tqr\tx1401\f1\fs20\tab UDC 57: 61\par
\pard\nowidctlpar\ri52\sl-187\slmult0\qr CODEN PDBIAD\par
\pard\nowidctlpar\sl-187\slmult0\qj\tqr\tx1401\tab ISSN 0031-5362\par
\pard\nowidctlpar\ri19\sl-1137\slmult0\qj\fs84\par
\pard\nowidctlpar\sl-129\slmult0\f0\fs12\par
\pard\nowidctlpar\li6384\ri321\sl-230\slmult0\qj\f1\fs20 Original scientific paper\par
\pard\nowidctlpar\sl-1036\slmult0\f0\fs103\par
\pard\nowidctlpar\fi1156\li220\ri417\sl-316\slmult0\qc\b\f1\fs32 Protection of acute hepatotoxicity in mice by Interleukin-la. - the role of Interleukin-S and Prostaglandin E2\par
\pard\nowidctlpar\li220\ri398\sl-446\slmult0\qj\tx1924\b0\fs16\tab MARIJA RENIC1, FILIP CULO' and DOMAGOJ SABOLOVIC2\par
\pard\nowidctlpar\sl-182\slmult0\f0\fs18\par
\pard\nowidctlpar\li3964\ri4296\sl-139\slmult0\qj\f1\fs10 Received February 2, 1995.\par
\pard\nowidctlpar\sl-240\slmult0\f0\fs24\par
\pard\nowidctlpar\li19\ri19\sl-192\slmult0\qj\b\f1\fs16 INTRODUCTION\par
\pard\nowidctlpar\li19\ri19\sl-244\slmult0\qj\b0\f0\fs24\par
\pard\nowidctlpar\ri19\sl-196\slmult0\qj\b\f1\fs20 MATERIALS AND METHODS\par
\pard\nowidctlpar\sl-230\slmult0\b0\f0\fs23\par
\pard\nowidctlpar\fi240\li9\ri52\sl-196\slmult0\qj\f1\fs20 In our previous investigations we have shown that IL-la is highly protective in mice with acute hepa\-tototoxicity induced by acetaminophen \fs22 (Paracetamol; \f0\fs20 AAP) \f1\fs22 (23), However, the mecha\-\fs20 nism(s) of the protective effect of IL-Ia in this, as well as in other models of acute tissue damage (22, 25), is still unknown, Since IL-la induces the synthe\-sis of various mediators (9), some of which have hepatoprotective effects, several mechanisms might be involved (23). One of the them might be mediated by prostaglandin E2 (PGE2), since exoge\-\par
\pard\nowidctlpar\fi240\li9\ri52\sl-201\slmult0\qj nously added PGE? is protective in vivo in rodents\par
\pard\nowidctlpar\fi240\li9\ri52\sl-196\slmult0\qj with chemically-induced acute hepatotoxicity (24, 28), and IL-l a induces the synthesis of PGEz in liver cells (8, 14, 23). Another mechanism might be medi\-ated by interleukin-6 (lL-6), since IL-6 has trophic ef\-fect on liver cells (1, 17, 19) and IL-la induces its synthesis in liver (8) and in other \i (20, \i0 26) cells. Moreover, IL-la induces the synthesis of nitric ox\-ide (NO) (13) and acute phase proteins (5), which also have hepatoprotective effects (3, 7). Finally, the protective effect of IL-l a might be simply due to its inhibitory effect on cytochrome P-450 mixed oxidas\-es (6), the enzymes converting AAP in liver in its ac\-tive metabolite (21).\par
\pard\nowidctlpar\fi240\li9\ri52\sb124\sl-196\slmult0\qj However, although highly suggestive, none of the above mentioned mechanisms have been proven. In this communication we investigated the hepatopro\-tective effect of IL-la in mice with AAP-induced hepatotoxicity in which the action of PGE2 and IL-6 was selectively blocked by administration of specif\-ic antibodies. We also investigated the effect of re\-combinant mouse IL-6 in the same model. Finally, we tested the effect of IL-la in a model of hepato\-toxicity, independent from action of cytochrome 450 oxidases, i.e. in mice given lipopolysaccharide (LPS) after presensitization with D-galactosamine (12).\par
\pard\nowidctlpar\fi240\li9\ri52\sb124\sl-494\slmult0\qj\f0\fs49\par
\pard\nowidctlpar\ri76\sl-196\slmult0\qj\f1\fs20 Abbreviations: AM acetaminophen; DGaIN, D( +)\-galactosamine hydrochloride; LPS, lipopoly\-saccharide; AST, aspartate aminotransferase; ALT, alanine aminotransferase;\par
\pard\nowidctlpar\ri76\sl-244\slmult0\qj\f0\fs24\par
\pard\nowidctlpar\li4\ri3609\sl-326\slmult0\qj\b\f1\fs20 Animals\par
\pard\nowidctlpar\fi240\li4\ri52\sb115\sl-211\slmult0\qj\b0\i CBNH \i0 Zgr inbred mice were raised in an animal colony unit at the Department of Physiology, School of \fs22 Medicine, Zagreb. Mice of both sexes aged \f2\fs20 12-16 \f1 weeks, weighing 20-25 g, were used. They were kept under standard laboratory conditions, fed with commercially available murine food pellets (K-l, Domzale, Slovenia) and given water ad \i libitum.\par
\pard\nowidctlpar\fi240\li4\ri52\sb115\sl-340\slmult0\qj\i0\f0\fs34\par
\pard\nowidctlpar\li14\ri1473\sl-326\slmult0\qj\b\f1\fs20 Induction of hepatitis with AAP\par
\pard\nowidctlpar\fi235\li9\ri57\sb115\sl-211\slmult0\qj\b0 The procedure of Guarner et al. (14) was fol\-lowed with slight modifications. Mice were given phenobarbitone-sodium (Kemika, Zagreb, Croatia) in drinking water during 7 days (0.3 g/L) in order to induce hepatic drug-metabolizing enzymes. Thereafter, mice were fasted overnight and AAP (0.5 ml) was given intragastrically by a stomach tube. Animals were allowed food 4 h later. Dose of the drug was either 200 or 300 mg/kg as indicated under Results. The dose of 300 mg/kg AAP induces a 71 %-79% mortality and the dose of 200 mg/kg about 10% mortality.\par
\pard\nowidctlpar\fi235\li9\ri57\sb115\sl-297\slmult0\qj\f0\fs29\par
\pard\nowidctlpar\li9\ri460\sl-321\slmult0\qj\b\f1\fs20 Induction of hepatitis with DGalN and LPS\par
\pard\nowidctlpar\fi230\li9\ri67\sb110\sl-211\slmult0\qj\b0 Mice were given i.p. an injection of 650 mg/kg DGalN in a volume of 0.2 ml. One hour later they re\-ceived i.p. 0.01 mg/kg (0.2 flg/mouse) LPS.\par
\pard\nowidctlpar\fi230\li9\ri67\sb110\sl-292\slmult0\qj\f0\fs29\par
\pard\nowidctlpar\li4\ri3489\sl-326\slmult0\qj\b\f1\fs20 Reagents\par
\pard\nowidctlpar\fi230\ri72\sb115\sl-211\slmult0\qj\b0 Pure AAP substance was donated by the Krka Pharmaceutical Company (Novo Mesto, Slove\-nia). AAP was dissolved in heated PBS to which 1-2 drops of 'TWeen 80 were added. Half mL of the suspension was thereafter administered intra\-gastric ally. Recombinant human IL-la (rhIL-la; 117 -271 Ro 24-5008, lot IL-l 2/88, sp. act. 3xlOB UI mg) was kindly provided by Dr Peter Lomedico (Hoffmann-La Roche Inc., New York), by courtesy\par
\pard\nowidctlpar\sl-412\slmult0\f0\fs41\par
\pard\nowidctlpar\li4\ri19\sl-235\slmult0\qj\i\fs18 Period bioI, Vol \i0 97, \i No \i0 1, 1995\par
\pard\nowidctlpar\li4\ri19\sl-445\slmult0\qj\fs44\par
\pard\nowidctlpar\ri19\sl-182\slmult0\qj\f1\fs20 55\par
\pard\nowidctlpar\f0\fs10\par
\pard\nowidctlpar\sl-196\slmult0\qj\f1\fs14 Marija Renic et al.\par
\pard\nowidctlpar\fi220\sl-220\slmult0\qj\fs20 of \i Dr \i0 A. Marusic (Dept. Anatomy, School of Medi\-cine, Zagreb). Recombinant mouse IL-6 (rmIL-6) was obatined from Genzyme (TEBU, Paris, France). A stock solutions of rhIL-l a and rmIL-6 were prepared in 0.2% BSA in pyrogen-free saline, aliquoted and stored at -70\'b0C. They were diluted immediately before use and injected intraperitoneally in a volume of 0.2 ml. Control animals were simultaneously given 0.2 ml pyrogen-free saline. D( + )-Galactosamine hydro\-chloride (DGalN) and LPS from Salmonella enteriti\-dis were purchased from Sigma (St. Louis, Missouri, USA), and anti-PGE2 polyclonal antibodies from Se\-ragen (Boston, Mass, USA). DGalN and LPS were dissolved in sterile pyrogen-free saline and injected i.p. in a dose of 0.2 rnl. Liophylized anti-PGE2 anti\-bodies were reconstituted to the original volume (20 ml) with PBS, injected Lp. in a dose of 0.2 ml. Mono\-clonal anti-mouse IL-6 antibodies were ascites super\-natants from rat hybridomas 6B4 growing in nude mice. Precipitated immunoglobulin fraction was dis\-\par
\pard\nowidctlpar\sl-220\slmult0\qj solved in saline and Lp. injected to mice in volume of 0.2 ml.\par
\pard\nowidctlpar\sl-211\slmult0\qj\b Plasma ALT and AST concentrations\par
\pard\nowidctlpar\fi216\sl-216\slmult0\qj\b0 ALT and AST concentrations were measured 24 hrs after the AAP administration. Plasma samples were obtained by a procedure in which hemolysis was undetectable. Mice were given 250 U heparin i.p. 15 min before bleeding. Blood was obtained by puncture of the medial \i eye \i0 angle with heparinized glass capillary tubes. Plasma was stored at -20\'b0C for 24 h before aminotransferase determination. AST and ALT levels were determined by standard laboratory techniques \i (10, \i0 11).\par
\pard\nowidctlpar\ri3096\sl-350\slmult0\qj\b IL-6 bioassay\par
\pard\nowidctlpar\fi225\sb134\sl-216\slmult0\qj\b0 IL-6 activity in plasma was measured with the 7TD 1 cell proliferation assay (32). Serial dil u\-tions of the samples were incubated -in triplicate with \i 3000 \i0 7TDl cells for 72 hours in 96-well micro titer plates. MTT (3-/4.5-dimethyl-thiazole\-2-ylj2.5-diphenyltetrazolium bromide) was add\-ed. Three hours later the supernatant was dis\-carded and the cells were lysed with dimethyl sulfoxide. The plates were read in microplate reader (570 nm). The optical density of the sam\-ples was compared with a standard curve generated from serial dilutions of murine rIL-6.\par
\pard\nowidctlpar\li4\ri2582\sl-355\slmult0\qj\b Statistical analysis\par
\pard\nowidctlpar\fi230\sb134\sl-220\slmult0\qj\b0 The results are expressed as mean:!: S.E.M. Para\-metric variables were compared by Student's t-test. Differences in survival between the groups of mice were compared by chi-square test, using Yates's cor\-rection of the test when indicated.\par
\pard\nowidctlpar\sl-182\slmult0\qj 56\par
\pard\nowidctlpar\sl-201\slmult0\qj\fs16 Hepatoprotective effect of IL-I a\par
\pard\nowidctlpar\sl-192\slmult0\qj\b\fs20 RESULTS\par
\pard\nowidctlpar\sl-225\slmult0\qj The effect \i of \i0 IL-\f3 1\'e1\f1  on serum level \i of \i0 IL-6 in mice given AAP\par
\pard\nowidctlpar\fi216\sl-211\slmult0\qj\b0 We have shown previously that IL-la increases the synthesis of PGE2 in liver tissue of AAP-pre\-treated mice (23). In this experiment we investigat\-ed the effect of the same cytokine on IL-6 synthesis in the AAP-pretreated mice. Saline \i or \i0 IL-la (l000 U/mouse i.p.) were administered to mice 2 hours before the AAP (300 mg/kg). This dose and time of administration of IL-l a was previously shown to have the maximal hepatoprotective effect (23). IL-6 concentration was determined 2 hours after AAP administration in plasma of a group of 6. At the same time, control IL-6 level was determined in 6 untreated mice. As presented in Table 1, IL-6 was detectable in normal mice and its level was slight\-ly, but not significantly, increased in saline-pre\-treated mice given AAP The administration of \f3 IL-1\'e1\b\f1  \b0  before AAP significantly increased IL-6 level in comparison to normal mice (p < 0.01). These re\-sults are very similar to that obtained by giving \f3 IL-1\'e1\b\f1  \b0  to normal mice (20).\par
\pard\nowidctlpar\fi1742\sl-230\slmult0 TABLE 1\par
\pard\nowidctlpar\sl-230\slmult0\i Serum level of \i0 11-6 \i in mice pretreated with 11-la be\-fore AAP\par
\pard\nowidctlpar\sl-153\slmult0\qj\i0\fs18 Treatment\par
\pard\nowidctlpar\fi-278\li278\sl-360\slmult0\qj\ul\fs12 IL-6level (pg/ml)b\par
\pard\nowidctlpar\li278\ri326\sb182\sl-177\slmult0\qj\ulnone\fs16 135 :!: 59 183 :!: 33\par
\pard\nowidctlpar\li278\ri254\sl-177\slmult0\qj 374 :!: 38c\par
\pard\nowidctlpar\sl-182\slmult0\qj\fs12 Normal mice Saline + AAP IL-Ia + AAP\par
\pard\nowidctlpar\sl-172\slmult0 " Saline or IL-Ia (1000 U/mouse i.p.) were administered \i to\par
\pard\nowidctlpar\sl-172\slmult0\qj\tx144\i0\tab mice i. p. 2 hrs before AAP (300 mg/kg) administration\par
\pard\nowidctlpar\sl-172\slmult0 b \fs18 Determined 2 hrs after MP administration (Mean :!:\par
\pard\nowidctlpar\sl-172\slmult0\qj\tx144\fs12\tab SEM, n = 6)\par
\pard\nowidctlpar\sl-172\slmult0\fs16 c p < 0.01\par
\pard\nowidctlpar\ri331\sl-206\slmult0\qj\b\fs20 The influence \i of \i0 anti-PGE2 and anti-IL-6 anti\-bodies on hepatoprotective effect \i of \i0 IL-l\f3\'e1\f1\par
\pard\nowidctlpar\fi235\sb172\sl-206\slmult0\qj\b0 The AAP heptotoxicity was assessed by measur\-ing serum ALT and AST levels 24 hours after adminis\-tration of the \i drug \i0 (200 mg/kg). Before AAP, different groups of mice (6 mice per group) were given Lp. either saline, IL-la (l000 U/mouse i.p.), anti-PGE2 antibodies \i (0.2 \i0 ml/mouse), anti-IL-6 antibodies \i (0.4 \i0 mg/mouse), combination of IL-l a and anti- PGE2 anti\-bodies or IL-la and anti-IL-6 antibodies (Table 2). Saline and IL-la were given 2 hours before AAP, and anti-PGE2 and anti-IL-6 antibodies 3 hours before IL\-Ia, i.e. 5 hours before AAP\par
\pard\nowidctlpar\fi230\sb81\sl-206\slmult0\qj As Table 2 shows, IL-la significantly decreased both AST and ALT levels in comparison to mice given saline before AAP (p < 0.01 and p < 0.05, respectively). Anti-PGE2 antibodies, when given alone before AAp, had no significant effect on ami\-\par
\pard\nowidctlpar\sl-235\slmult0\qj\i\f0\fs18 Period bioI, Vol \i0 97, \i No \i0 1, 1995\par
\pard\nowidctlpar\fs10\par
\pard\nowidctlpar\sl-211\slmult0\qj\fs14 Marija.Renic et al.\par
\pard\nowidctlpar\fi1804\ri1732\sl-302\slmult0\qj\lang1033\f4\fs20 TABLE\'a3..\par
\pard\nowidctlpar\sb100\sl-201\slmult0\qj\lang1050\i\f1 The influence of anti-PGE\sub 2\nosupersub  (PGE\sub 2\nosupersub ) and anti\--mouse /L-6 (a-m/L-6) antibodies on hepatoprotec\-\fs22 tive effect of /L-1 a in mice given \i0 a \i lethal dose \f0\fs20 of AAP\par
\pard\nowidctlpar\sl-163\slmult0\qj\i0\fs12 Serum aminotransferase levelb\par
\trowd\trgaph10\trleft-10\trrh244\trbrdrl\brdrs\brdrw10 \trbrdrt\brdrs\brdrw10 \trbrdrr\brdrs\brdrw10 \trbrdrb\brdrs\brdrw10 \trpaddl10\trpaddr10\trpaddfl3\trpaddfr3
\clvertalc\cellx1262\clvertalc\cellx2721\clvertalc\cellx3830\pard\intbl\nowidctlpar\qc\fs14 Pretreatment'\cell AST (U/L)\cell ALT (UIL)\cell\row\trowd\trgaph10\trleft-10\trrh249\trbrdrl\brdrs\brdrw10 \trbrdrt\brdrs\brdrw10 \trbrdrr\brdrs\brdrw10 \trbrdrb\brdrs\brdrw10 \trpaddl10\trpaddr10\trpaddfl3\trpaddfr3
\clvertalc\cellx1262\clvertalc\cellx2721\clvertalc\cellx3830\pard\intbl\nowidctlpar\qc Normal mice\cell 75 :t 4\cell 23 :t I\cell\row\trowd\trgaph10\trleft-10\trrh182\trbrdrl\brdrs\brdrw10 \trbrdrt\brdrs\brdrw10 \trbrdrr\brdrs\brdrw10 \trbrdrb\brdrs\brdrw10 \trpaddl10\trpaddr10\trpaddfl3\trpaddfr3
\clvertalc\cellx1262\clvertalc\cellx2721\clvertalc\cellx3830\pard\intbl\nowidctlpar\qc Saline\cell\pard\intbl\nowidctlpar\li264\ri24 1157:t 151\cell\pard\intbl\nowidctlpar\qc 1047 :t 128\cell\row\trowd\trgaph10\trleft-10\trrh177\trbrdrl\brdrs\brdrw10 \trbrdrt\brdrs\brdrw10 \trbrdrr\brdrs\brdrw10 \trbrdrb\brdrs\brdrw10 \trpaddl10\trpaddr10\trpaddfl3\trpaddfr3
\clvertalc\cellx1262\clvertalc\cellx2721\clvertalc\cellx3830\pard\intbl\nowidctlpar\qc IL-Ia\cell\pard\intbl\nowidctlpar\li264\ri24 336 :t 32e\cell\pard\intbl\nowidctlpar\qc 536 :t 64"\cell\row\trowd\trgaph10\trleft-10\trrh201\trbrdrl\brdrs\brdrw10 \trbrdrt\brdrs\brdrw10 \trbrdrr\brdrs\brdrw10 \trbrdrb\brdrs\brdrw10 \trpaddl10\trpaddr10\trpaddfl3\trpaddfr3
\clvertalc\cellx1262\clvertalc\cellx2721\clvertalc\cellx3830\pard\intbl\nowidctlpar\qc a-PGEz\cell\pard\intbl\nowidctlpar\li264\ri24 1162 :t 243\cell\pard\intbl\nowidctlpar\qc 920 :t 83\cell\row\trowd\trgaph10\trleft-10\trrh163\trbrdrl\brdrs\brdrw10 \trbrdrt\brdrs\brdrw10 \trbrdrr\brdrs\brdrw10 \trbrdrb\brdrs\brdrw10 \trpaddl10\trpaddr10\trpaddfl3\trpaddfr3
\clvertalc\cellx1262\clvertalc\cellx2721\clvertalc\cellx3830\pard\intbl\nowidctlpar\qc a-PGE2\fs20  +\fs16  IL-Ia\cell\pard\intbl\nowidctlpar\li264\ri24\fs14 656 :t 10ged\cell\pard\intbl\nowidctlpar\qc 750 :t 65d\cell\row\trowd\trgaph10\trleft-10\trrh177\trbrdrl\brdrs\brdrw10 \trbrdrt\brdrs\brdrw10 \trbrdrr\brdrs\brdrw10 \trbrdrb\brdrs\brdrw10 \trpaddl10\trpaddr10\trpaddfl3\trpaddfr3
\clvertalc\cellx1262\clvertalc\cellx2721\clvertalc\cellx3830\pard\intbl\nowidctlpar\qc a-mIL-6\cell\pard\intbl\nowidctlpar\li264\ri24 1385 :t 239\cell\pard\intbl\nowidctlpar\qc 1497:t 164\cell\row\trowd\trgaph10\trleft-10\trrh153\trbrdrl\brdrs\brdrw10 \trbrdrt\brdrs\brdrw10 \trbrdrr\brdrs\brdrw10 \trbrdrb\brdrs\brdrw10 \trpaddl10\trpaddr10\trpaddfl3\trpaddfr3
\clvertalc\cellx1262\clvertalc\cellx2721\clvertalc\cellx3830\pard\intbl\nowidctlpar\qc a-mlL-6\fs20  +\fs16  IL-Ia\cell\fs14 NDe\cell 844 :t 67d\cell\row\pard\nowidctlpar\sl-177\slmult0\qj\fs12 'Saline or IL-Ia (1000) U/mouse) were administered to mice i.p. 2 hrs before AAP administration (200 mg!kg). Anti-PGEz and anti-mouse IL-6 antibodes were given i. p. 3 hrs before IL-I a.\par
\pard\nowidctlpar\ri158\sl-259\slmult0\qj\fs10 h \fs14 Determined 24 hrs after AAP administration (Mean :t SEM, n = 6). \fs10 e \fs14 Significant difference (p < 0.05 or better) to saline pretreated mice. \fs6 d \fs14 Significant difference (p < 0.05) to IL-Ia\par
\pard\nowidctlpar\ri3648\sl-259\slmult0\qj\fs8 e \fs14 Not done.\par
\pard\nowidctlpar\sl-196\slmult0\qj\f1\fs20 notransferase \f0\fs18 levels. However, when given before IL-l a they partially abrogated its protective effect, i.e. serum aminotransferase levels were higher than in mice pretreated with IL-l a alone but lower than in mice pretreated with saline. Anti-IL-6 antibodies in\-jected alone increased slightly (but not significant\-ly) both AST and ALT levels. When given before IL\-Ia, as judged by determination of only AST level, these antibodies partially eliminated its protective effect, Le. AST level was midway between the level in mice pretreated with IL-la alone and the level in mice pretreated with saline.\par
\pard\nowidctlpar\fi230\sb96\sl-196\slmult0\qj These data show that both anti-PGE2 and anti-IL-6 antibodies partially abrogate the hepatoprotective effect ofIL-l \f1\fs20 a.\par
\pard\nowidctlpar\ri321\sl-201\slmult0\b\fs18 The influence of rmIL-6 anti anti-mIL-6 monoclonal antibodies on mortality and serum aminotransferase level in mice with AAP-induced hepatotoxicity\par
\pard\nowidctlpar\fi235\sb120\sl-201\slmult0\qj\b0 Mice were given rmIL-6 (10000 U/mouse i.p.) 2 hours and anti-mIL-6 monoclonal antibodies (0.4 \fs20 mg/mouse Lp.) 3 hours \f0\fs18 before MP \f1\fs20 (300 mg/kg). Mortality was followed-up for 48 hours \f0\fs18 and the se\-rum AST and ALT levels were determined \f1\fs20 24 \f0\fs18 hours after MP administration. As seen in Table \f1 3, \f0 rmIL-6 significantly decreased the mortality and ami\-notransferase levels in comparison to control \f1\fs20 mice treated with saline (p < \f0\fs18 0.001 \f1\fs20 and p < 0.01, respec\-tively). \f0\fs18 On the \f1\fs20 contrary, the administration \f0\fs18 of mono\-\f1 clonal anti-IL-6 antibodies before MP increased \fs20 slightly both the mortality \f0\fs18 of \f1\fs20 mice (from \f0\fs18 53% to \f1 69%) \f0 and the serum AST and ALT levels \f1 (p > 0.05 and p < 0.05, respectively). When the same antibodies\par
\pard\nowidctlpar\sl-235\slmult0\qj\i\f0 Period bioI, Vol \i0 97, \i No \i0 1, 1995\par
\pard\nowidctlpar\sl-192\slmult0\qj\f1\fs14 Hepatoprotective \f0 effect of \f1 IL-I \f0\fs10 IX\par
\pard\nowidctlpar\sl-158\slmult0\qj\fs16 TABLE 3.\par
\pard\nowidctlpar\sl-172\slmult0\qj\i\fs12 Influence \i0 of \i rmIL-6 and anti mIL-6 monoclonal antibodies on mortality and serum aminotransferase level \i0 in mice \i with AAP-induced hepatotox\-\i0\fs16 icity\par
\trowd\trgaph10\trleft-10\trrh249\trbrdrl\brdrs\brdrw10 \trbrdrt\brdrs\brdrw10 \trbrdrr\brdrs\brdrw10 \trbrdrb\brdrs\brdrw10 \trpaddl10\trpaddr10\trpaddfl3\trpaddfr3
\clvertalc\cellx2106\clvertalc\cellx4199\pard\intbl\nowidctlpar\qc\fs14 Pretreatment' No of dead mice!\cell\pard\intbl\nowidctlpar\li24\qr Serum aminotransferase levelb\cell\row\trowd\trgaph10\trleft-10\trrh220\trbrdrl\brdrs\brdrw10 \trbrdrt\brdrs\brdrw10 \trbrdrr\brdrs\brdrw10 \trbrdrb\brdrs\brdrw10 \trpaddl10\trpaddr10\trpaddfl3\trpaddfr3
\clvertalc\clbrdrb\brdrw10\brdrs \cellx786\clvertalc\clbrdrb\brdrw10\brdrs \cellx2106\clvertalc\clbrdrb\brdrw10\brdrs \cellx3196\clvertalc\clbrdrb\brdrw10\brdrs \cellx4199\pard\intbl\nowidctlpar\fs24\cell\pard\intbl\nowidctlpar\qc\fs12 'Ibtal No of mice (%)\cell\fs14 AST (UL)\cell ALT (UIL)\cell\row\trowd\trgaph10\trleft-10\trrh288\trbrdrl\brdrs\brdrw10 \trbrdrt\brdrs\brdrw10 \trbrdrr\brdrs\brdrw10 \trbrdrb\brdrs\brdrw10 \trpaddl10\trpaddr10\trpaddfl3\trpaddfr3
\clvertalc\clbrdrt\brdrw10\brdrs \cellx786\clvertalc\clbrdrt\brdrw10\brdrs \cellx2106\clvertalc\clbrdrt\brdrw10\brdrs \cellx3196\clvertalc\clbrdrt\brdrw10\brdrs \cellx4199\pard\intbl\nowidctlpar\ri24 Saline\cell\pard\intbl\nowidctlpar\qc 19/36 (53)\cell\pard\intbl\nowidctlpar\li24\ri249\qr 1180 :t 260\cell\pard\intbl\nowidctlpar\qc 1303 :t 224\cell\row\trowd\trgaph10\trleft-10\trrh182\trbrdrl\brdrs\brdrw10 \trbrdrt\brdrs\brdrw10 \trbrdrr\brdrs\brdrw10 \trbrdrb\brdrs\brdrw10 \trpaddl10\trpaddr10\trpaddfl3\trpaddfr3
\clvertalc\cellx786\clvertalc\cellx2106\clvertalc\cellx3196\clvertalc\cellx4199\pard\intbl\nowidctlpar\ri24 rmlL-6\cell\pard\intbl\nowidctlpar\qc 2/20 (10)\f1  r\cell\pard\intbl\nowidctlpar\li24\ri249\qr\f0 390:t IOle\cell\pard\intbl\nowidctlpar\qc 431 :t 84e\cell\row\trowd\trgaph10\trleft-10\trrh177\trbrdrl\brdrs\brdrw10 \trbrdrt\brdrs\brdrw10 \trbrdrr\brdrs\brdrw10 \trbrdrb\brdrs\brdrw10 \trpaddl10\trpaddr10\trpaddfl3\trpaddfr3
\clvertalc\cellx786\clvertalc\cellx2106\clvertalc\cellx3196\clvertalc\cellx4199\pard\intbl\nowidctlpar\ri24 a-mIL-6\cell\pard\intbl\nowidctlpar\qc 22/32 (69)\cell\pard\intbl\nowidctlpar\li24\ri249\qr 1413 :t 224\cell\pard\intbl\nowidctlpar\qc 1863 :t 206d\cell\row\trowd\trgaph10\trleft-10\trrh168\trbrdrl\brdrs\brdrw10 \trbrdrt\brdrs\brdrw10 \trbrdrr\brdrs\brdrw10 \trbrdrb\brdrs\brdrw10 \trpaddl10\trpaddr10\trpaddfl3\trpaddfr3
\clvertalc\cellx786\clvmgf\clvertalc\clbrdrb\brdrw10\brdrs \cellx2106\clvmgf\clvertalc\clbrdrb\brdrw10\brdrs \cellx3196\clvmgf\clvertalc\clbrdrb\brdrw10\brdrs \cellx4199\pard\intbl\nowidctlpar\ri24 a-mIL-6\cell\pard\intbl\nowidctlpar\qc 10/20 (50)\cell NO"\cell NDe\cell\row\trowd\trgaph10\trleft-10\trrh172\trbrdrl\brdrs\brdrw10 \trbrdrt\brdrs\brdrw10 \trbrdrr\brdrs\brdrw10 \trbrdrb\brdrs\brdrw10 \trpaddl10\trpaddr10\trpaddfl3\trpaddfr3
\clvertalc\cellx786\clvmrg\clvertalc\clbrdrt\brdrw10\brdrs \cellx2106\clvmrg\clvertalc\clbrdrt\brdrw10\brdrs \cellx3196\clvmrg\clvertalc\clbrdrt\brdrw10\brdrs \cellx4199\pard\intbl\nowidctlpar\ri24 (30 ' ,70\'b0C)\cell\cell\cell\cell\row\pard\nowidctlpar\sl-177\slmult0\qj\fs16 'Saline \f2\fs14 or rmlL-6 (10000 U/mouse) \f0 were \f2\fs16 administered to mice i.p. 2 \fs14 hrs before MP administration. Anti-mIL-6 antibodies were given i.p. 3 hrs before AAP.\par
\pard\nowidctlpar\ri177\sl-254\slmult0\qj\fs12 b \fs16 Determined 24 hrs after AAP administration (Mean :t SEM, n = 6) \fs12 e \fs16 Not done.\par
\pard\nowidctlpar\sl-182\slmult0\qj\fs14 d.e.! p < 0.05, p < 0.01 and p < 0.001 in comparison to saline treated mice, respectively.\par
\pard\nowidctlpar\sl-196\slmult0\qj\f1\fs20 were heat-inactivated (30 minutes in water bath at \fs18 70\'b0C) they lost their activity, \f0\fs16 i.e. \f1\fs18 they had no effect on \fs20 mortality of mice (50% vs. 53% mortality in compari\-son to saline-treated mice). The data show that IL-6 has strong hepatoprotective effect.\par
\pard\nowidctlpar\ri216\sl-201\slmult0\b The effect of IL-I\f3\'e1\f1  on mortality of mice with hepatotoxicity induced with D-GaIN and LPS\par
\pard\nowidctlpar\fi240\sb115\sl-201\slmult0\qj\b0\fs22 Saline or IL-lex (1000 U/mouse \f0\fs20 i.p.) were \f1\fs22 given to \fs20 mice 2 hours before D-GalN (650 mg/kg i.p.). One hour after D-GaLN the same mice were given LPS (0.2 /lg/mouse i.p.). Table 4 shows that all mice pre\-treated with saline died within 24 hours after LPS administration. Pretreatment with IL-l a significantly reduced the mortality of mice given DGalN and LPS (mortality 3/15 vs. 15/15 in control mice; p < \fs22 0.0001). No additional deaths \f0\fs20 were \f1\fs22 seen in this \fs20 group within the next 48 hours. The data show that IL-la is also highly protective in hepatotoxicity in\-duced by LPS in DGalN presensitized mice.\par
\pard\nowidctlpar\sl-153\slmult0\qj\f0\fs16 TABLE 4.\par
\pard\nowidctlpar\sl-288\slmult0\qj\ul\i\fs12 The effect \i0 of \i IL-l a on hepatotoxicity induced by DGaIN and LPS'.\par
\pard\nowidctlpar\sb110\sl-177\slmult0\qj\tx2942\ulnone\i0\fs14\tab Mortality\par
\pard\nowidctlpar\fi115\li2572\ri196\sl-177\slmult0\qc\f2\fs16 No of \f1 dead \f2\fs14 mice/ Total No of mice (%)e\par
\pard\nowidctlpar\sl-163\slmult0\qj Treatmentb\par
\fs12 Saline \f0\fs18 + \fs14 DGalN + LPS\par
\pard\nowidctlpar\sl-192\slmult0\qj\f2\fs16 15/15 (100)\par
\pard\nowidctlpar\sl-158\slmult0\qj IL-Ia \fs20 + \fs14 DGalN \f0\fs18 + LPS\par
\pard\nowidctlpar\sl-196\slmult0\qj\f2\fs14 3/15 (20)d\par
\pard\nowidctlpar\sl-172\slmult0 'Mice were given 650 mg!kg DGalN i.p. and one hour later 0.01 mg!kg (0.2/lg/mouse) LPS i.p:\par
\pard\nowidctlpar\sb129\sl-172\slmult0 h Saline or IL-Ia (1000 U/mouse or 166 ng!kg) were given i.p. 2 hrs be\-fore DGalN administration\par
\pard\nowidctlpar\sl-278\slmult0\qj\f0\fs6 e \fs12 Mortality was recorded after \f2\fs14 24 hrs. \fs8 d \fs16 p < 0.0001\par
\pard\nowidctlpar\sl-177\slmult0\qj\f0 57\par
\pard\nowidctlpar\li4\ri3086\sl-196\slmult0\qj\f1 Marija Reni\'e6 et aI.\par
\pard\nowidctlpar\li4\ri3086\sl-364\slmult0\qj\f0\fs36\par
\pard\nowidctlpar\ri3110\sl-192\slmult0\qj\b\f1\fs20 DISCUSSION\par
\pard\nowidctlpar\ri3110\sl-124\slmult0\qj\b0\f0\fs12\par
\pard\nowidctlpar\fi230\ri52\sl-196\slmult0\qj\f1\fs20 In the presented experiments we confirmed the previous results that IL-l a is highly protective in AAP-induced acute hepatotoxicity (23). Since IL-la inhibits the function of cytochrome P-450 mixed oxi\-dases (6), and AAP is metabolized in liver in an ac\-tive form by these enzymes (21), the protective ef\-fect of IL-l a may simply be due to the inhibition of conversion of AAP in active moiety. However, this is most probaby not the mechanism of its protective effect, since IL-la was protective in a model of hepatotoxicity which is independent of action of cy\-tochrome P-450 oxidases, i.e. in mice given LPS af\-ter sensitization with LPS (Table 4). In the latter model, D-galactosamine inhibits RNA synthesis and thus prevents the synthesis of protective proteins against damage inflicted by LPS (16).\par
\pard\nowidctlpar\fi235\ri52\sb148\sl-196\slmult0\qj It is known that IL-la stimulates the production of PGE in the liver cells \i (B, \i0 14, 23) and that exoge\-noush applied PGE\sub 2\nosupersub  is hepatoprotective (24, 27, \i 28). \i0 Here we have shown that anti-PGE2 antibodies, as judged by change of aminotransferase level, par\-tially cancel the protective effect of IL-la in AAP-in\-duced hepatotoxicity (Table 2). However, PGE2 might not be only protastnoide involved in IL-la me\-diated hepatoprotection. Indeed, others have shown that PGI2 is highly protective in mice with MP-induced hepatotoxicity (at much lower dose than PGE2) and that thromboxane Az (T~) might cause hepatic damage (14). In line with this, we have found that liver fragments from mice pretreat\-ed with IL-l a before administration of AAP produce \i in vitro \i0 increased amounts of PGE2 and PGI2 and decreased amounts of TxA2 (unpublished data). Obviously, to assesss the role of prostanoids in IL\--1a mediated protection of hepatotoxicity, one needs to use specific antibodies to or specific antagonists of these prostanoids as well.\par
\pard\nowidctlpar\fi235\li9\ri52\sb148\sl-196\slmult0\qj Other mediator in IL-l a- induced protection might be IL-6. This cytokine has been shown to con\-tribute to the radioprotective effect of IL-l on he\-matopoietic cells (22). Here we have shown that IL\--1a  stimulates the synthesis of IL-6 in mice with AAP\-induced hepatotoxicity (Table 1). Others have shown the same effect of IL-la in normal mice \i (20). \i0 Anti-IL-6 antibodies partially cancelled the protec\-tive effect of IL-la in mice with AAP-induced hepato\-toxicity (Table 2). Since IL-6 has general hepa\-totrophic effect (2, 17), we investigated the effect of this cytokine in hepatoprotective mechanisms \i by \i0 blocking the action of spontaneusly produced IL-6 (i.e., \i by \i0 use anti-IL-antibodies without exogenous stimulation with IL-la), as well as \i by \i0 following the effect of exogenously added cytokine (T'able 3). The administration of recombinant IL-6 highly reduced the mortality of mice and serum aminotransferase level, while the blocking action of spontaneously produced IL-6 had the opposite effect. Thus, all these data clearly show that IL-6 is, at least in this model of hepatotoxicity, beneficial to damaged liver cells, i.e. hepatoprotective. This is in agreement with some clinical observations \i (30).\par
\pard\nowidctlpar\fi235\li9\ri52\sb148\sl-878\slmult0\qj\i0\f0\fs87\par
\pard\nowidctlpar\li19\ri4123\sl-182\slmult0\qj\f1\fs20 58\par
\pard\nowidctlpar\li2097\ri43\sl-196\slmult0\qj\fs16 Hepatoprotective \i effect of \i0 IL- I a\par
\pard\nowidctlpar\li2097\ri43\sl-360\slmult0\qj\f0\fs36\par
\pard\nowidctlpar\fi235\ri52\sl-206\slmult0\qj\f1\fs20 Recently, there appeared data showing that mono\-clonal anti-IL-6 antibodies do not block, but actually increase concentrationion of bioactive IL-6 in the se\-rum (15, 31). Indeed, in our preliminary experiments, using the same antibodies and the dose, we have shown that anti-IL-6 antibodies greatly (up to 18 times) increase the level of bioactive IL-6 in sera of AAP-treated mice. Thus, our data with anti-IL-6 anti\-bodies might be intepreted as speaking in favour of pathogenic (hepatodamaging) role of IL-6 in acute hepatotoxicity \i (1B, \i0 29). However, despite of in\-creased level of bioactive IL-6 after administration of anti-IL-6 andtibodies, the data obtained after exoge\-nously added recombinant IL-6 clearly show that this cytokine is, at least in this model of hepatotoxicity, beneficial to damaged liver cells, i.e. hepato\-protective. Even more, IL-6 might be a more distal mediator in protective cascade then the prostaglan\-dins, since PGE2 is shown to induce the synthesis of IL-6 (4, 33).\par
\pard\nowidctlpar\fi235\ri52\sl-1161\slmult0\qj\f0\fs116\par
\pard\nowidctlpar\li9\ri3043\sl-192\slmult0\qj\f1\fs20 REFERENCES\par
\pard\nowidctlpar\li9\ri3043\sl-307\slmult0\qj\f0\fs30\par
\pard\nowidctlpar\fi-225\li292\ri72\sl-192\slmult0\qj\f1\fs16 I. AKERMAN 8 COTE 8 YANG S Q, McCLAIN C, NELSON S, BAGBY G ], DIEHL A M \f2 1992 \f1 Antibodies to tumor necrosis factor-alpha inhibit liver regeneration after partial hepatectomy. \i Am j Physiol 263(4PtI):G \i0\f2 679-685\par
\pard\nowidctlpar\fi-225\li292\ri72\sl-196\slmult0\qj\f0\fs19\par
\pard\nowidctlpar\li52\ri43\sl-192\slmult0\qj\f1\fs16 2. AKIRA \f2 D, \f1 TAGA \f2 T, \f1 KISHIMOTO \f2 T 1993 \f1 Interleukin-6 in\par
\pard\nowidctlpar\li52\ri24\sl-192\slmult0\qj\tx240\tab biology and medicine. \i Adv ImmunoI54: \i0\f2 1-78\par
\pard\nowidctlpar\li52\ri24\sl-196\slmult0\qj\f0\fs19\par
\pard\nowidctlpar\fi-240\li297\ri72\sl-192\slmult0\qj\f1\fs16 3. ALCORN] M, FIERER J, CHO]KIER M 1992 The acute\-phase response protects mice from D-galactosamine sensitization to endotoxin and tumor-necrosis factor\-a. \i Hepatology \i0\f2 15: 122-129\par
\pard\nowidctlpar\fi-240\li297\ri72\sl-196\slmult0\qj\f0\fs19\par
\pard\nowidctlpar\fi-240\li297\ri72\sl-192\slmult0\qj\f1\fs16 4. BAILLY S, FERRUA, FAY M, GOUGEROT-POCIDALO M A 1990 Differential regulation of IL 6, IL la, IL-IB and TNFa production in LPS-stimulated human mono \fs12 cytes: Role of cyclic AMP. \i Cytokine \i0 3: 205-210\par
\f0\fs19\par
\pard\nowidctlpar\li62\ri48\sl-192\slmult0\qj\f1\fs16 5. BAUMAN H, GAULDIE \f2 ] 1994 \f1 The acute phase re\-\par
\pard\nowidctlpar\li62\ri28\sl-192\slmult0\qj\tx235\tab sponse. \i Immunol Today \i0\f2 15: 74-80\par
\pard\nowidctlpar\li62\ri28\sl-196\slmult0\qj\f0\fs19\par
\pard\nowidctlpar\fi-240\li297\ri57\sl-187\slmult0\qj\f1\fs16 6. BERTINI R, BIANCHI M, ERROl A, VILLA 8 GHEZZI \f2 P 1989 \f1 Dexamethasone modulation of in vivo effects of endotoxin, tumor-necrosis factor and IL-I on liver \i cy\-\i0 tochrome \f2 P450, \f1 plasma fibrinogen and serum iron. \i j \i0\fs12 Leuk \i BioI \i0 46: \f2 254-262\par
\pard\nowidctlpar\fi-240\li297\ri57\sl-216\slmult0\qj\f0\fs21\par
\pard\nowidctlpar\fi-235\li292\ri81\sl-187\slmult0\qj\f1\fs16 7. BILLIAR T R, CURRAN R D, HARBRECHT B G, \fs18 STUEHR D ], DEMETRIS A J, SIMMONS R L \f2\fs16 1990 \f1 Modulation of nitrogen oxide synthesis in vitro: N\'b0\-monomethyl-L-arginine inhibits endotoxin-induced ni\-trite/nitrate biosynthesis while promoting hepatic damage. \i j \i0 Leuk \i\f2 BioI \i0 48: 565-569\par
\pard\nowidctlpar\fi-235\li292\ri81\sl-211\slmult0\qj\f0\fs21\par
\pard\nowidctlpar\li52\ri52\sl-192\slmult0\qj\f2\fs16 8. DECKER K 1993 \f1 Mechanisms and mediators in hepatic\par
\pard\nowidctlpar\li52\ri33\sl-192\slmult0\qj\tx235\fs12\tab necrosis. \i Gastroenterologia japonica \i0\f2 4: 20-25\par
\pard\nowidctlpar\li52\ri33\sl-384\slmult0\qj\f0\fs38\par
\pard\nowidctlpar\li1723\ri52\sl-240\slmult0\qj\i\fs18 Period bioI, Vol \i0 97, \i No \i0 1, 1995\par
\pard\nowidctlpar\li9\ri3100\sl-196\slmult0\qj\f1\fs14 Marija Renic et aI.\par
\pard\nowidctlpar\li9\ri3100\sl-374\slmult0\qj\f0\fs37\par
\pard\nowidctlpar\li43\ri67\sl-192\slmult0\qj\f1\fs16 9. DlNARELLO C A \f2 1991 \f1 Interleukin-I and interleukin-I\par
\pard\nowidctlpar\li24\ri28\sl-192\slmult0\qj\tx268\fs14\tab antagonism. \i\f2 Blood \i0 77: \f1\fs12 1627-1652\par
\pard\nowidctlpar\fi-268\li292\ri76\sb144\sl-192\slmult0\qj\fs16 10. EXPERT PANEL 'ON ENZYMES, Comittee on Stan\-dards (lFCC) 1977 Provisional recommendations on IFCC methods for the measurement of catalytic con cent ration of enzymes part 2. IFCC method for aspar\-\fs12 tate ami-notransferase \i ] Clin Chem Biochem \i0\f2 15: 39-51\par
\pard\nowidctlpar\fi-268\li292\ri76\sb144\sl-364\slmult0\qj\f0\fs36\par
\pard\nowidctlpar\fi-264\li297\ri72\sl-192\slmult0\qj\f1\fs16 II. \f2 EXPERT \f0 PANEL ON ENZYMES \f1 (lFCC) 1980 Provi\-sional recommendations on IFCC methods for the measure-ment of catalytic concentrations of enzymes.\par
\pard\nowidctlpar\li33\ri24\sl-192\slmult0\qj\tx268\tx782\tx1430\tx1766\tx2400\tx4008\tab IFCC\tab method\tab for\tab alanine\tab aminotransferase.\i\tab Clin\par
\pard\nowidctlpar\li297\ri72\sl-192\slmult0\qj ChemActa \f2 105: \i0 147F-154F\par
\pard\nowidctlpar\li297\ri72\sl-230\slmult0\qj\f0\fs23\par
\pard\nowidctlpar\fi-264\li297\ri76\sl-192\slmult0\qj\fs16 12. FREUDENBERG M A, GALANOS C \f2 1991 \f1\fs18 Tumor necro\-\fs16 sis factor alpha mediates lethal activity of killed Gram\-negative and Gram-positive bacteria in D-galac\-\fs12 tosamine-treated mice. \i Infect Immun \i0\f0\fs10 59:21 10-211512.\par
\pard\nowidctlpar\fi-264\li297\ri76\sl-230\slmult0\qj\fs23\par
\pard\nowidctlpar\fi-268\li297\ri76\sl-196\slmult0\qj\fs16 13. GELLER D A, NUSLER A K, DI SILVIO M, LOWEN\-STEIN C j, SHAPIRO R A, WANG S C, SIMMONS R L, DlLLIAR T R 1993 Cytokines, endotoxin, \f1\fs18 and glucocor\-\fs16 ticoids regulate the expression of inducibile nitric \f0 oxide \f1 synthase in hepatocytes. \i Proc Nat Acad \f0 Sci USA \fs12 50: \i0 522-526\par
\pard\nowidctlpar\fi-268\li297\ri76\sl-206\slmult0\qj\fs20\par
\pard\nowidctlpar\fi-264\li297\ri76\sl-196\slmult0\qj\fs16 14. GUARNER F, BOUGHTON-SMITH N K, BLACKWELL \fs18 G j, MONCADA S \f2\fs16 1988 \f0\fs18 Reduction \f1 by prostacyclin of \fs16 acetaminophen-induced liver toxicity in the mouse. \i\f2\fs14 Hepatology \i0 8: \f0\fs12 248-253\par
\pard\nowidctlpar\fi-264\li297\ri76\sl-211\slmult0\qj\fs21\par
\pard\nowidctlpar\fi-264\li302\ri67\sl-196\slmult0\qj\fs14 15. HERMANS H, DILLEN C, PUT W, VAN DAMME j, BILLAU A 1992 \f1 Protective effect of anti-interleukin \f0 (lL)-6 \f1 antibody against endotoxin, associated with \fs16 paradoxically increased \f0\fs14 IL-6 \f1\fs16 levels. \i\f2\fs14 Eur ] Immunol \i0 22: \f0 2395-240 I\par
\pard\nowidctlpar\fi-264\li302\ri67\sl-201\slmult0\qj\fs20\par
\pard\nowidctlpar\fi-254\li292\ri67\sl-192\slmult0\qj\fs18 16. KEPPLER D, PAUSCH j, DECKER K \f2\fs16 1974 \f1\fs18 Selective uri\-\fs16 dine triphosphate deficiency induced by D-galac\-tosamine in liver and reversed by pyrimidine nucle\-otide precursors: effect on ribonucleic acid synthesis. \i ] Biol \f2 Chem \i0 249: 211-216\par
\pard\nowidctlpar\fi-254\li292\ri67\sl-230\slmult0\qj\f0\fs23\par
\pard\nowidctlpar\fi-264\li307\ri67\sl-192\slmult0\qj\f2\fs16 17. KOGA \f0 M, OGASAWARA \f1 h 1991 Induction of hepato\-cytes mitosis in intact adult rat by interleukin-Ia and interleukin-6. \i\f2 Life Sci \i0 49: 1263-1270\par
\pard\nowidctlpar\fi-264\li307\ri67\sl-220\slmult0\qj\f0\fs22\par
\pard\nowidctlpar\fi-264\li307\ri67\sl-192\slmult0\qj\fs16 18. KUKUMU S, FUKATSU A, SHINAGAWA, KUROKAWA S, KUSAKABE \f2 A 1992 \f1 Localization of intrahepatic interleukin 6 in patients with acute and chronic liver disease. \i\f2 ] Clin Fathol \i0 45: 408-411\par
\pard\nowidctlpar\fi-264\li307\ri67\sl-220\slmult0\qj\f0\fs22\par
\pard\nowidctlpar\fi-264\li307\ri48\sl-192\slmult0\qj\f2\fs16 19. KUMA S, INABA M, OGATA \f0 H \f2 1990 \f1 Effect of human recombinant interleukin-6 on the proliferation of mouse\par
\pard\nowidctlpar\li43\sl-192\slmult0\qj\tx264\tx1243\tx1521\tx1891\tx3244\tab hepatocytes\tab in\tab the\tab primary \f2 culture.\i\tab Immunabialogy\par
\pard\nowidctlpar\li307\ri48\sl-192\slmult0\qj 180: \i0 235.242\par
\pard\nowidctlpar\li307\ri48\sl-220\slmult0\qj\f0\fs22\par
\pard\nowidctlpar\fi-278\li312\ri76\sl-196\slmult0\qj\f2\fs16 20. LIBERT \f0 C, BROUCKEART P, SHAW A, FRIERS \f2 W 1990 \f1\fs18 Induction of interleukin 6 by human and murine \f2\fs16 re\-\f1 combinant interleukin I in mice. \i\f2 EurJ Immunol 20: \i0 691-694\par
\pard\nowidctlpar\fi-278\li312\ri76\sl-187\slmult0\qj\f0\fs18\par
\pard\nowidctlpar\li24\ri72\sl-201\slmult0\qj\fs16 21. MITCHELL j R, jOLLOW D j, POTTER W Z, DAVIS D\par
\pard\nowidctlpar\li24\ri24\sl-201\slmult0\qj\tx278\tab C, GILLETTE j R, BRODIE B B 1973 Acetaminophen\-\par
\pard\nowidctlpar\li24\ri24\sl-422\slmult0\qj\fs42\par
\pard\nowidctlpar\ri1771\sl-235\slmult0\qj\i\fs18 Period bioI, Vol \i0 97, \i No \i0 1, 1995\par
\pard\nowidctlpar\li2083\ri302\sl-192\slmult0\qj\f1\fs14 Hepatoprotective \f0 effect \f1\fs16 of IL- I a\par
\pard\nowidctlpar\li2083\ri302\sl-384\slmult0\qj\f0\fs38\par
\pard\nowidctlpar\li278\ri288\sl-201\slmult0\qj\f1\fs16 induced hepatic necrosis: role of drug metabolism. \i ] Pharmacal Exp Ther \f2 187: \i0 185-194\par
\pard\nowidctlpar\li278\ri288\sl-177\slmult0\qj\f0\fs17\par
\pard\nowidctlpar\fi-268\li268\ri321\sl-196\slmult0\qj\f2\fs16 22. NETA R, PERLSTEIN R, VOGEL S N, LEDNEY \f0 G D, \f2 ABRAMS \f0 j \f2 1992 Role \f1 of interleukin 6 (lL-6) in protec tion from lethal irradiation and in endocrine responses to IL-I and tumor necrosis factor. \i ] Exp Med \i0 175: \f2 689\-694\par
\pard\nowidctlpar\fi-268\li268\ri321\sb177\sl-196\slmult0\qj\fs18 23. RENIC \f0 M, CULO \f2 F, BILIC \f0 A, BUKOVEC Z, \f2\fs16 SABOLOVIC \f0 D, \f2\fs18 ZUPANOVIC Z 1993 \f1\fs16 The effect of interleukin la on\par
\pard\nowidctlpar\ri273\sl-196\slmult0\qj\tx278\tx2140\tx3360\tx4190\fs18\tab acetaminophen-induced\tab hepatotoxicity.\i\f2\fs16\tab Cytokine\i0\tab 5:\par
\pard\nowidctlpar\li268\ri321\sl-196\slmult0\qj 192-197\par
\pard\nowidctlpar\li268\ri321\sl-321\slmult0\qj\f0\fs32\par
\pard\nowidctlpar\fi-273\li273\ri312\sl-196\slmult0\qj\f2\fs16 24. RENIC \f0 M, CULO \f2 F, BILIC \f0 A, CULjAK K, \f2 SABOLOVIC \f0 D, jAGIC \f2 V 1992 \f1 Protection of acetaminophen-induced \fs18 hepatotoxicity in \f0\fs16 mice \f2\fs18 by PGE,. \i Croat] Gastroenterol \fs16 Hepatoll: \i0 59-64\par
\pard\nowidctlpar\fi-273\li273\ri312\sl-220\slmult0\qj\f0\fs22\par
\pard\nowidctlpar\fi-273\li278\ri326\sl-192\slmult0\qj\f2\fs16 25. ROBERT \f0 A, OLAFSSON A S, LANCASTER C, ZHANG \f2 W 1990 \f1 Interleukin-I is cytoprotective, antisecretory, stimulates PGE, synthesis by the stomach, and retards gastric emptying. \i\f2 Life Sci \i0 48: 123-134\par
\pard\nowidctlpar\fi-273\li278\ri326\sl-196\slmult0\qj\f0\fs19\par
\pard\nowidctlpar\fi-278\li283\ri321\sl-196\slmult0\qj\f2\fs16 26. SHALABY M R, WAAGE A, AARDEN L, ESPEVIK T 1989 \f1 Endotoxin, tumor necrosis factor-a and \fs18 interleukin-I induce interleukin 6 production in \f0\fs16 vivo. \i\f2 Clin Immunol Immunapathol \i0 53: 488-498\par
\pard\nowidctlpar\fi-278\li283\ri321\sl-187\slmult0\qj\f0\fs18\par
\pard\nowidctlpar\fi-273\li278\ri321\sl-192\slmult0\qj\f2\fs16 27. SINCLAIR S B, \f0 LEVY \f2 G A 1991 \f1 Treatment of fulminant viral hepatic failure with prostaglandin E. A prelimi\-\fs14 nary report. \i Dig \i0 Dis \i Sci \i0 36: \f2\fs12 791-800\par
\pard\nowidctlpar\fi-273\li278\ri321\sl-201\slmult0\qj\f0\fs20\par
\pard\nowidctlpar\fi-278\li283\ri326\sl-196\slmult0\qj\f2\fs16 28. STACHURA \f0 j, \f2 TARNAWSKI \f0\fs18 A, \f2 IVEY \f0 K j, MACH T, \fs16 BOGDAL j, SZCZUDRAWA j \f2 1981 \f1 Prostaglandin pro\-tection of carbon tetrachloride-induced liver cell ne\-\fs12 crosis in the rat. \i Gastroenterology \f2 81: \i0 2 I 1-217\par
\pard\nowidctlpar\fi-278\li283\ri326\sl-187\slmult0\qj\f0\fs18\par
\pard\nowidctlpar\fi-273\li283\ri321\sl-192\slmult0\qj\f2\fs16 29. SUN Y, TOKUSHIGE \f0\fs14 K, \f2\fs16 ISONO E, YAMAUCHI Y, \f0\fs14 OBATA H \f2 1992 \f1 Elevated interleukin-6 levels in patients with acute hepatitis. \i\f2 ] Clin Immunol12: \i0 197-200\par
\pard\nowidctlpar\fi-273\li283\ri321\sl-196\slmult0\qj\f0\fs19\par
\f2\fs16 30. TOVEY \f0 M G, GUGENHEIM j, GUYMARHO j \f2 1991 \f1 Genes for interleukin-l, interleukin-6 and tumor-ne\-crosis factor are expressed at markedly reduced lev\-els in the livers in patients with severe liver diseases. \i\fs12 Autoimmunity \f2 10: \i0 297-310\par
\pard\nowidctlpar\fi-273\li283\ri321\sl-182\slmult0\qj\f0\fs18\par
\pard\nowidctlpar\fi-278\li288\ri326\sl-192\slmult0\qj\f2 31. TRUYENS \f0 C, ANGELO-BARRIOS A, TOR \f2\fs16 RICO \f0\fs18 F, VAN \fs16 DAMME 1. HEREMANS H, CARLIER \f2\fs18 Y 1994 \f1\fs16 Interleukin-6 (11-6) production in mice infected with Trypanosoma cruzi: Effect of its paradoxical increase by anti-IL-6 monoclonal antibody treatment on infec\-tion and acute-phase and humoral immune responses. \i\f2 Infect Immunal \i0 62: 692-696\par
\pard\nowidctlpar\fi-278\li288\ri326\sl-206\slmult0\qj\f0\fs20\par
\pard\nowidctlpar\fi-278\li288\ri326\sl-192\slmult0\qj\f2\fs16 32. VAN SNICK \f0 j, CAYPHAS S, VINK A \f2 1986 \f1 Purification and NH,-terminal amino acid sequence of T-cell-de\-rived lymphokine with growth factor activity for B.cell hybridomas. \i Proc Natl Acad \f2 Sci (USA) \i0 83: 9679-9683\par
\pard\nowidctlpar\fi-278\li288\ri326\sl-172\slmult0\qj\f0\fs17\par
\pard\nowidctlpar\fi-278\li288\ri312\sl-196\slmult0\qj\f2\fs16 33. ZHANG Y, LIN j X, YIP Y K, VILCEK \f0\fs14 j \f2\fs16 1988 \f0\fs14 Enhancement of cAMP \f1\fs16 levels and of protein kinase activity by tumor \fs14 necrosis factor and interleukin I in human fibroblasts: \f0 Role in the induction of interleukin 6. \i Proc Nati \f1 Acad \f2 Sci \i0 85: 6802-6805\par
\pard\nowidctlpar\fi-278\li288\ri312\sl-465\slmult0\qj\f0\fs46\par
\pard\nowidctlpar\li4080\ri19\sl-182\slmult0\qj\f5\fs16 5~\par
\pard\nowidctlpar\li33\ri19\sl-196\slmult0\qj\f1\fs14 Marija Reni6 et aI.\par
\pard\nowidctlpar\ri19\sl-192\slmult0\qj\fs16 Hepatoprotective effect of IL-l \i a\par
\pard\nowidctlpar\sl-288\slmult0\i0\f0\fs28\par
\pard\nowidctlpar\fi-153\li196\ri129\sl-278\slmult0\b\f1\fs16 r-- ABSTRACT\par
\pard\nowidctlpar\li196\ri129\sl-278\slmult0\b0\i\fs20 Protection of \i0 acute \i hepatotoxicity \i0 in \i mice by interleukin-la \i0 - the \i role of interleukin-6 \i0 and \i prostaglandin Ez\par
\pard\nowidctlpar\fi230\li196\ri72\sb72\sl-206\slmult0\qj Background \i0 and \i Purpose. We have shown previously that lL-la is highly protective in mice with acute hepatototoxicity induced by AAP In these experiments we investigated whether PGEz \i0 and lL-6 \i are involved in\par
\pard\nowidctlpar\li196\ri19\sl-206\slmult0 lL-la-induced hepatoprotection. In addition, we investigated the effect \i0 of \i spontaneously produced \i0 lL-6 \i on AAP-induced hepatotoxicity; \i0 and \i the ef\-fect \i0 of \i lL-la on heptotoxicity induced by LPS in D-galactosamine sensi\-tized mice.\par
\pard\nowidctlpar\fi235\li196\ri72\sl-206\slmult0\qj Materials \i0 and \i Methods. The mice received toxic dose \i0 of \i AAP by gas\-tric route. Recombinant human lL-la or recombinant mouse \i0 lL-6 \i were given to mice \i0 i.p. 2 \i hours before AAP, polycolnal anti.PGEz \i0 and \i mono\-clonal anti-lL-6 antibodies were given \i0 3 \i hours before lL.l a, or, when given alone, \i0 5 \i hours before AAP The mortality \i0 of \i mice was followed, \i0 and \i serum aminotransferase levels (AST \i0 and \i ALT) were determined \i0 24 \i hours after the AAP administration.\par
\pard\nowidctlpar\fi230\li196\ri72\sl-206\slmult0\qj Results. lL-l a significantly reduced \i0 and \i the serum ALT \i0 and \i AST levels in the AAP-treated mice. It also decreased the mortality \i0 of \i mice which re\-ceived LPS after D-galactosamine. Pretreatment \i0 of \i mice with anti-PGEz or anti-lL-6 antibodies before lL-la administration decreased its protective effect in those with AAP-induced hepatotoxicity Administration \i0 of \i anti-lL-6 antibodies alone before AAP increased the mortality \i0 of \i mice \i0 and \i the se\-\i0 rum \i aminotransferase levels, while, in..contrast, administration \i0 of \i recomb \i0 i\-\i nant mouse \i0 lL-6 \i before AAP had the \i0 opposite, \i i.e. beneficial effect.\par
\pard\nowidctlpar\fi240\li196\ri57\sl-206\slmult0\qj Conclusion. Both PGEz \i0 and lL-6 \i mediate, perhaps in mutually interde\-pendent way, the hepatoprotective effect \i0 of \i lL-l a.\par
\pard\nowidctlpar\fi240\li196\ri57\sl-590\slmult0\qj\i0\f0\fs59\par
\pard\nowidctlpar\li24\ri48\sl-177\slmult0\qj\f1\fs14 lDepartment of Physiology and Immunolo\-gy, School of Medicine, Salata 3, Zagreb, Croatia;\par
\pard\nowidctlpar\li24\ri48\sl-134\slmult0\qj\f0\fs13\par
\pard\nowidctlpar\li19\ri52\sl-177\slmult0\qj\f1\fs16 2INSERM Unite 313, Groupe Pitie\-\fs12 SalpetriEre, 911 Bd de ]'H6pital, \f2 75013 \f1\fs14 Par\-\fs16 is, France;\par
\pard\nowidctlpar\li19\ri52\sl-355\slmult0\qj\f0\fs35\par
\pard\nowidctlpar\ri24\sl-177\slmult0\f1\fs16 Correspondence:\par
\fs14 Marija Reni6\par
Department of Physiology and Immunolo\-gy, School of Medicine, Salata 3, Zagreb, Croatia;\par
\pard\nowidctlpar\ri24\sl-2260\slmult0\f0\fs226\par
\pard\nowidctlpar\ri57\sl-201\slmult0\qj\b\f1\fs20 Key words: \b0 acetaminophen, hepatotoxicity, interleukin-l ex, interleukin-6, prostaglandin E2' D-galactosamine, lipopolysac\-charide.\par
\pard\nowidctlpar\sl-7296\slmult0\f0\fs729\par
\pard\nowidctlpar\ri19\sl-182\slmult0\qj\fs18 60\par
\pard\nowidctlpar\ri19\sl-7324\slmult0\qj\fs732\par
\pard\nowidctlpar\ri19\sl-254\slmult0\qj\i\fs18 Period bioI, Vol \i0 97, \i No \i0 1, 1995\par
}