الفهرس | Only 14 pages are availabe for public view |
Abstract Aim: Endogenous estradiol is required for the normal cellular growth of the kidney and maintenance of its function. In this study, an animal model of menopause, bilateral ovariectomy, was used to evaluate the influence of the exogenous estradiol on kidney functions in female rats. Methods: Fifty mature female Sprague-Dawley albino rats 3 months old and 110-160 g body weight were used. The rats were fed on casein- based diet. After acclimation, forty females were subjected to bilateral ovariectomy under effect of ketamine and xylazine at doses (ketamine 80 mg /kg i.p, xylazine 10 mg/kg i.p), respectively. Sham operation was performed on another ten female rats. 21 days after ovariectomy, the rats were randomly divided into four groups in addition to sham operated group (ten for each group). group I, n=10, sham operated rats which received daily corn oil only subcutaneously for 2 months. group II, n =10, they were ovariectomized rats, received daily corn oil only subcutaneously for 2 months. group III, n= 10, were ovariectomized rats which received daily 25µg /kg estradiol benzoate (EB) subcutaneously in the form of Folone in corn oil (1: 50 V/V). group IV, n=10, were ovariectomized rats which received daily 50µg /kg EB subcutaneously in the form of Folone in corn oil (1: 50 V/V). group V, n=10, were ovariectomized rats which received daily 100µg /kg EB subcutaneously in the form of Folone in corn oil (1: 50 V/V). The treatment continued for 2 months. The following parameters were measured; food consumption, weight gain, relative kidneys weight, glomerular filtration rate (GFR), urine volume, urine sodium (Na+ ), urine potassium (K+ ), serum Na+ , serum K+ , renal malondialdehyde (MDA), renal reduced glutathione (GSH), gene expression of aquaporin 2 (AQP2) by RT-PCR as well as histopathology of renal tissue. Results: The results showed that exogenous estrogen administration significantly reduced food consumption, weight gain and, urine volume, urine Na+, serum K+ and MDA. Also, it increased relative kidneys weight, urine K+, serum Na+, GSH, AQP2 gene expression and GFR (improved only after 2 months). Histopathological examination showed that E2 administration by the three doses revealed shrinkage of glomerulus, hydropic degeneration of renal tubules, increased space of glomerulus and congestion of inter-tubular blood capillaries especially after 2 months. Conclusions: Administration of EB with 25 μg/kg dose was the best dose that may mitigate ovariectomy induced renal dysfunctions but it doesn’t reach the effect of physiological endogenous estrogen. However, the doses 50 and 100 μg/kg EB failed to reduce these dysfunctions especially at 2 months. |