The protective roles of zinc and estradiol in renal ischemia/ reperfusion injury in ovariectomized rats

Abstract

Context: One of the main events associated with ischemia/reperfusion injury (IRI) is excessive production of reactive oxygen species (ROS). Zinc (Zn) and estradiol are considered as antioxidants that scavenge free radicals. Objectives: The aim of this study was to compare the protective effect of Zn and estradiol against renal IRI in ovariectomized rats. Materials and Methods: Ovariectomized Wistar rats were randomly divided into five experimental groups including control (sham operated), IRI, estradiol treated +IRI, estradiol and Zn treated +IRI, Zn treated +IRI groups. The IRI was induced by clamping renal vessels for 45 minutes followed by 24 hours reperfusion. During the last 6 hours of reperfusion, urine output was collected and the measurements were performed. Results: IRI caused an increase in kidney tissue damage score (KTDS) significantly (P<0.05). The serum levels of blood urea nitrogen (BUN) and the creatinine (Cr) also elevated by IRI, but theses parameters attenuated by Zn treatment significantly (P<0.05). Cr-clearance and urine flow were increased by Zn, and the percent of sodium excretion was increased by estradiol significantly (P<0.05). The kidney tissue level of malondialdehyde was decreased by co-treatment of Zn and estradiol statistically (P<0.05). Conclusions: Zn protected the kidney against IRI with an evident improvements of serum BUN and Cr levels, Cr clearance and tissue damage.

Keywords

• zinc
• rat
• ischemia-rep
• estradiol