Naslov
Reduced dietary zinc and selenium levels impairs vascular function via oxidative stress in Sprague-Dawley rats aortas

Autori
Čavka, Ana ; Novak, Sanja ; Mihaljević, Zrinka ; Grizelj, Ivana ; Ćosić, Anita ; Lončarić, Zdenko ; Popović, Brigita ; Drenjančević, Ines

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Acta Physiologica Volume 211, Issue Supplement s697 / - , 2014, 51-S4-E6

Skup
FEPS (Federation of European Physiological Societies) 2014

Mjesto i datum
Budimpešta, Mađarska, 27.08.2014. - 30.08.2014

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
selenium ; zinc ; vascular reactivity ; acetylcholine ; hypoxia ; rat

Sažetak
Objective:Trace elements zinc (Zn) and selenium (Se) are important components of antioxidative enzymes. The aim of this study was to determine if reduced dietary Zn and Se levels affect vascular function by increasing oxidative stress. Materials and Methods: Thirty three male Sprague Dawley rats were fed with 4 types of custom made rat chow (Faculty of Agriculture University of Osijek, Croatia) from weaning for 10 weeks: a) high Zn(70.81 mg/kg)-high Se (0.363 mg/kg) (N=5) ; b) high Zn(70.81 mg/kg)- low Se(0.043 mg/kg) group (N=10) ; c) low Zn(30.16 mg/kg)-high Se (0.363 mg/kg) group (N=10) and d) low Zn(28.56 mg/kg)-low Se(0.030 mg/kg) group (N=8). Prior to decapitation, rats were anesthetized with 75 mg/kg ketamine+2.5 mg/kg midazolam. Dose responses to ACh (10-9- 10-5 M) and response to reduced pO2 (bath gas mixture containing N2 95%, CO2 5%) were tested in noradrenaline-precontracted aortic rings in the absence/presence of the NOS inhibitor L- NAME, COX-1, 2 inhibitor indomethacin (INDO) and superoxide scavenger Tempol in tissue bath. To test differences among groups Two-way ANOVA or One-way ANOVA was used when appropriate (SigmaPlot v11.2, Systat Software, Chicago, USA). Results:ACh induced relaxation (AchIR) was reduced in low Zn-low Se group compared to other groups (P <0.001 for 10-8-10-5M ACh).L- NAME blocked AChIR in all groups of rats (P <0.01 for 10-8-10-5M ACh), while INDO reduced AChIR only in low Zn-high Se group (P <0.5 for 10-7-10-5M ACh). Tempol improved AChIR in low Zn-low Se group (P <0.01 for 10-7-10- 5M ACh). Hypoxia induced relaxation (HIR) was increased in high Zn-low Se group compared to high Zn- high Se group and low Zn-low Se group (P <0.05). While INDO significantly blocked HIR in all groups of rats except high Zn-high Se group, L-NAME and TEMPOL did not have significant effect on HIR in any group of rats. Conclusion:Zn and Se dietary deficiency affects vascular reactivity. Since AChIR (predominantly mediated by NO) is more affected than HIR (predominantly mediated by COX- 1, 2 metabolites), data suggest that that increased oxidative stress decreases NO bioavailability in rat aortas thus affecting NO-mediated response.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

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