engleski

Comparasion between the effects of dopamine drugs on gastric, liver lesion as well as on duodenal and liver lesions induced in two suitable experimental rat models

The beneficial effect of dopamine (D) on gastroduodenal as well as liver lesion is well known. Noteworthy, their relationship has not been simultaneously studied in the same experimental model, Therefore, we applied in rats D agonists (DAG) bromocriptine (B) (10) and amantadine (AM) (20) or D antagonists (DAN) haloperidol (H) and and domperidone (DOMP) (both 5 mg/kg b.w.i.p.) 1 h before 6 hr- restraint stress (exp 1) or 48 h-restraint stress (exp.2) (gastric/liver lesions)as wellas 24 h-bile duct+hepatic artery ligation (exp.III) (duodenal/liver lesions)Gastrointestinal lesions were assessed as before (Eur. J. Pharmacol. e.g. 1988). Liver lesion were recorded semiquantitativly macro/microscopically concerning their their extent and severity (score 0-4. Exp.I Stomach: A strong protection was noted for both DAG, and significant aggravitation for both DAN, which could be inhibited by simultaneous coadministration of DAG. Liver: DAN strongly aggravated otherwise small lesion (vascular degeneratio and fatty accumulation in hepatocytes), an effect counteracted by simultaneus administration of DAG (exceptions DOMP and AM).Exp II: Stomach: No influence of D-drugs (both DAG and DAN) was noted. Liver: A strong protection was noted for both DAG, significantly inhibited by both DAN. Exp.III: Duodenum: A significant protection was found only for AM, but no further influence was demonstrated for any invastigated agent. Liver: B but not AM, strongly protected liver from severe ischaemic necrosis. This effect was inhibited by either H or DOMP. From these results we conclude that both beneficial effects of DAG, either stomach protection (exp.I. or liver protection (exp.III.) could be inhibited by DAN. Hence, the involment of D_mechanisms in both organs lesions seems likely. On the other hend, the effect of D-drugs were observed in gastrointestinal tract particulary in earlier period (6h), unlike their effects on liver noted after delayed (24 and 48 H). Likewise, some other effects of D-drugs, either DAG (lack of protection: liver:exp.1, stomach: exp.II or DAN (lack of aggravation: duodenum, liver:exp.III) point to the particular difference between them.

dopamine drugs; liver lesions; gastric lesions; duodenal lesions; experimental rat models

nije evidentirano