Effects of Morphine Dependency on the Ovarian Folliculogenesis Following Superovulation in Mice

Background: Opioids may affect hypothalamic GnRH secretion and Hypothalamic-Pituitary- Gonad axis, resulting in reproductive disturbances. Current study investigates the effects of morphine on structure of ovary following superovulalion through morphologic/morphometric studies. Methods: Twelve young female NMRI mice were allocated into treatment and control groups. Treatment group received oral morphine at final dose of 0.4mg/ml for 21 days. Physical dependency was proved by injection of naloxone (2mg/kg ip). The mice were superovulated by 10 iu PMSG (ip) and 48 hours later were sacrificed by cervical dislocation. Ovaries were removed and H&E staining was done. Every 10th serial section, which represents nonrandom 10 percent sample was counted. Follicles were classified into small, growing, antral and atretic according to the diameter and number of follicular cell layers surrounding oocytes. The volume and the weight of ovaries were recorded. In addition, the diameter of the antral follicles and oocytes was carefully measured by a calibrated oculometer. Results: The volume and the weight of ovaries showed no significant alterations in the two groups. The proportion of small and atretic follicles was statistically different in treatment and control groups (P<0.001). Conclusion: According to our data, oral morphine did not alter the volume and the weight of the ovary. However, folliculogenesis was moderately affected by morphine and following superovulation the behavior of ovaries in the treatment group is comparable to the control group.