The effects of estradiol and testosterone on renal tissues oxidative after central injection of angiotensin II in female doca - salt treated rats.

Background Although numerous studies have proven that estrogen (Est) has a protective effect on the development of hypertension, more research needs to be done to show its detailed mechanism in a variety of hypertension. The important role of active oxygen species in blood pressure is well defined. We examined whether or not sex hormones change the growth of reactive oxygen species (ROS) in kidneys after central microinjection of angiotensin II (Ang II). Materials and methods Female Wistar rats, 8 weeks old (200 ± 10 g) were used in this study. The animal groups were (1) Sham, (2) Ovariectomy (OVX), (3) Sham-Hypertension (Sham-Hyper), (4) OVX-Hypertension (OVX-Hyper), (5) Sham-Hyper-Est, (6) OVX-Hyper-Est ; (7) Sham-Hyper-Testosterone (Tst) and (8) OVX-Hyper-Tst. Solutions of 1% NaCl and 0.1 KCl were used and desoxycorticostrone (doca-salt) was injected (45 mg/kg) 3 times a week in Hypertension groups. Estradiol and Tst (2 mg/kg and 5 mg/kg ; daily; subcutaneously) for 4 weeks. Ang II (50 µM, 5 µL) was microinjected by intracerebroventricular ( i.c.v.) infusion and malondialdehyde (MDA) and thiol in the kidneys were measured. Results MDA in the kidneys was increased by Ang II and doca-salt treatments. Both estradiol and Tst decreased the kidney's MDA. The level of thiol was higher in Hyper groups and reversed after treatment with estradiol and Tst. Conclusions Our findings suggest that central effect of Ang II on blood pressure and kidney disease is accompanied with increased levels of oxidative stress in the kidneys. Indeed sex hormones change the ROS level in the kidneys after central microinjection of Ang II. .

Effect of Nigella sativa on ischemia-reperfusion induced rat kidney damage.

OBJECTIVES: There are a few previously reported studies about the effect of Nigella sativa oil on renal ischemia-reperfusion injury (IRI). The aim of the present study was to test the hypothesis whether pre- or post-treatment with N. sativa hydroalcoholic extract (NSE) would reduce tissue injury and oxidative damages in a clinically relevant rat model of renal IRI. MATERIALS AND METHODS: IRI was induced by clamping of bilateral renal arteries for 40 min fallowed by reperfusion for 180 min. NSE was prepared in a Soxhlet extractor and administrated with doses of 150 mg/kg or 300 mg/kg at 1 hr before ischemia induction (P-150 and 300) or at the beginning of reperfusion phase (T-150 and 300), via jugular catheter intravenously. The kidneys were then removed and subjected to biochemical analysis, comet assay or histopathological examination. RESULTS: The kidneys of untreated IRI rats had a higher histopathological score (P<0.001), while in P-150, as well as T-150 and T-300 groups tubular lesions significantly decreased (P<0.001). Pre- and post-treatment with NSE also resulted in a significant decrease in malondialdehyde (MDA) level (P<0.001) and DNA damage (P<0.001) that were increased by renal I/R injury. NSE treatment also significantly restore (P<0.01) the decrease in renal thiol content caused by IRI. CONCLUSION: The present study shows N. sativa extract has marked protective action against renal IRI, which may be partly due to its antioxidant effects.