the protective effect of γ‑aminobutyric acid on kidney injury induced by renal ischemia‑reperfusion in ovariectomized estradiol‑treated rats

Background: renal ischemia-reperfusion injury (iri) is one of the most important causes of kidney injury, which is possibly gender-related. this study was designed to investigate the role of g-aminobutyric acid (gaba) against iri in ovariectomized estradiol-treated rats. methods: thirty-five ovariectomized wistar rats were used in six experimental groups. the first three groups did not subject to estradiol treatment and assigned as sham-operated, control, and gaba-treated groups. gaba (50 μmol/kg) and saline were injected in the treated and control groups 30 min before the surgery, respectively. the second three groups received the same treatments but received estradiol valerate (500 μg/kg, intramuscularly) 3 days prior to the surgery. the iri was induced in the control and treated groups by clamping the renal artery for 45 min and then 24 h of reperfusion. all animals were sacrificed for the measurements. results: the serum levels of creatinine and blood urea nitrogen, kidney weight, and kidney tissue damage score significantly increased in the iri rats (p < 0.05). gaba significantly decreased the aforementioned parameters (p < 0.05). the uterus weight increased significantly in rats that received estradiol (p < 0.05). serum and kidney levels of nitrite (nitric oxide metabolite) did not alter significantly. serum level of malondialdehyde increased significantly in the ovariectomized rats exposed to iri (p < 0.05). conclusions: it seems that gaba improved iri in ovariectomized rats. estradiol was also nephroprotective against iri. however, co-administration of estradiol and gaba could not protect the kidney against iri.