Effect of testosterone supplementation on leptin release in rats after castration and/or unilateral surrenalectomy

The objective of this study was to examine the effect of testosterone supplementation on leptin release in rats which underwent castration and unilateral surrenalectomy.

The study was conducted on 80 adult male Wistar albino rats. Animals were divided into eight groups, with ten animals in each group. Group 1 was the Control group, Group 2 the Testosterone group, Group 3 the Castration group, Group 4 the Surrenalectomy group, Group 5 the Castration and Surrenalectomy group, Group 6 the Castration and Testosterone group, Group 7 the Surrenalectomy and Testosterone group, and Group 8 the Castration, Surrenalectomy and Testosterone group. The animals in Groups 2, 6, 7 and 8 were administered 5 mg/kg/day intramuscular testosterone propionate for four weeks. Blood samples were collected for analyses of leptin, LH, FSH and free and total testosterone levels in plasma.

Groups 3 and 5 had the highest leptin and LH levels of all the groups (p < 0.01). Leptin and LH levels in Groups 1 and 4 were higher than those in Groups 2, 6, 7 and 8 (p < 0.01). A comparison of groups with regard to plasma FSH levels showed that the concerned parameter was significantly higher in Groups 3 and 5 than in the other groups (p < 0.01). FSH levels in Groups 1 and 4 were lower than those in all other groups (p < 0.01). The highest testosterone levels were obtained in Groups 2, 6, 7 and 8 (p < 0.01). Testosterone levels in Groups 1 and 4 were higher than those in Groups 3 and 5 (p < 0.01).

This study demonstrates that unilateral surrenalectomy in rats does not have a significant effect on leptin release, while plasma LH levels, rather than testosterone, may be more effective on plasma leptin.