Sudy of theeffects of orchidectomy and testosterone and estradiol administration on lipids profile in male rats

Sex steroids have multiple roles in regulating of body lipid metabolism. The purpose of this study was to investigate the effects of orchidectomy and administration of testosterone and estradiol on lipid profile in male rats. In this experimental study, 40 male rats were divided into groups of 5 animals in each: control, orchidectomized, testosterone or estradiol receiving, orchidectomized testosterone receiving, estradiol receiving, orchidectomized estradiol receiving, sham and olive oil receiving rats. Testosterone enanthate (10µg/kg/day) and estradiol valerate (2µg/kg/day) were injected intraperitoneally. After 7 weeks, blood samples were obtained and serum levels of lipid profile were measured using spectrophotometry method. Data were analyzed using SPSS19 software and ANOVA. Serum level of triglyceride and VLDL significantly decreased in orchidectomized group compared to the control group (P<0.01). Serum LDL and HDL levels were not significantly changed in all groups compared with the control group. Compared to the control group, there was a significant decrease in serum cholesterol levels in orchiectomized (P<0.01), testosterone receiving (P<0.001), estradiol receiving orchiectomized (P<0.01), testosterone receiving orchidectomized (P <0.01) groups. The results of this study indicated that orchidectomy and decreased testosterone results in rapid decrease in cholesterol levels; however, testosterone or estradiol administration did not revert the cholesterol levels to its normal levels. Administration of testosterone causes decreased TG and VLDL levels, but did not significantly change lipid profile.