The protective effects of hormonal suppression by a gonadotropin-releasing hormone agonist or an oral contraceptive on the decreased ovarian reserve in female rats exposed to isotretinoin.

Abstract

The objective of our study was to evaluate whether ovarian suppression by two different hormonal methods may spare the ovary the cytotoxic effects of isotretinoin in a rat model. Four groups (n=8 Sprague-Dawley albino rats per group) were studied: control (Group I), 7.5 mg/kg/day isotretinoin (Group II), isotretinoin plus the combination of 0.030 mg ethinyl estradiol/0.15 mg levonorgestrel (combined oral contraceptive, COC), and isotretinoin plus 100 μg (microgram) leuprolide acetate (GnRHa) (Group III and IV, respectively). Four rats from each group were decapitated on the 30th day of treatment, and the remaining rats were decapitated on the 30th day of untreated follow-up. Serum anti-Mullerian hormone (AMH) concentrations, healthy and atretic follicle numbers, and apoptotic activity of follicles in oophorectomy specimens were compared between the groups. There were no significant differences in AMH levels among the study groups before, immediately after (first month), and one month after their last medication (second month) (p=0.08, 0.47, and 0.08, respectively). At the end of the first month, the control group had a higher median count of healthy primordial follicles compared to the study groups: 13.5 (8-22), 5.5 (3-11), 6 (2-13), and 1 (0-1) in control, isotretinoin, isotretinoin+COC, and isotretinoin+GnRHa groups, respectively (p=0.02). However, there was no statistically significant difference in the number of healthy primordial follicles between the groups one month after the last medication (p=0.33). The median atretic antral follicle counts in the first month were 2 (1-4), 3.5 (1-4), 0 (0-2), and 0 (0-0) in the control, isotretinoin, isotretinoin+COC, and isotretinoin+GnRHa groups, respectively (p=0.02). Otherwise, there were no significant differences in other types of follicles among the control and treated groups (p>0.05). There was also no statistical difference between the groups regarding immunostaining intensity for active caspase-3 evaluated in the first or second month of treatment (p=0.8 and 0.2, respectively). Our results show that GnRH agonists or COC have no protective effects on ovarian reserve when co-administered with isotretinoin in the rat model.