A Study on the Role of Gonadal Sex Hormones in the Regulation of Serum leptin level in Experimental Animals

This work was carried out to evaluate the influence of gonadectomy and sex steroids (estradiol and testosterone) on leptin level and to examine the possible relation between gender and serum leptin level.A total number of 48 adult white albino rats of both sexes were used this study. The animals were divided into three main groups. The first group was the control group. The second group was the gonadectomized group. The third group was gonadectomized animals treated with sex hormones (estrogen and testosterone) for two weeks. The animals were-sacrificed, blood was collected and serum was separated. Leptin, estradioland testosterone levels were estimated by radioimmunoassay.The results of the present study revealed that:Serum leptin levels were higher in female adult rats than in male adult rats of similar body weight.• Orchidectomy resulted in a significant elevation in serum leptin levels but ovariectomy resulted in a significant decrease in serum leptin levels.• Estrogen treatment causes a significant elevation in serum leptin levels in both male and female rats however, testosterone treatment causes a significant reduction in serum leptin level in male rats but not in female rats.Thus, it could be concluded that serum leptin concentrations in the rats dependent on gonadal function and gonadal hormones are important regulators of serum leptin level.