Inhibin B level changes during the follicular phase in rats with unilateral ovarian torsion

Objective: To investigate the association between duration of ovarian torsion and levels of serum inhibin B in an animal model. Materials and Methods: An animal model prospective study was conducted in a tertiary referral hospital and chemical pathology institute. Nineteen female Lewis rats were divided to four groups. In the first group, the control group, laparotomies alone were performed. In groups 2-4 laparotomies and right ovarian torsion for 720 degrees with fixation of the adnexa to the parietal peritoneum were performed. Blood samples were taken from the rat groups at 12, 24, and 36 hours after laparotomy. Inhibin B levels were measured by ELISA. Results: Serum mean ± SD inhibin B level in the control rats during the beginning of the metesterus, 12, 24, and 36 hours later were 108.4 ± 43.6, 129.5 ± 49.3, 99.07 ± 60.50, and 91.58 ± 27.74 pg/ml, respectively. Inhibin B levels in the control group increased 12 hours after the beginning of the metesterus, whereas in the study group, a decline in inhibin B levels was found at the same time. This difference was significant (p = 0.05). Inhibin B levels at 24 and 36 hours from the beginning of the metestrus did not show statistical difference. Conclusions: Unilateral ovarian torsion in rats changed the pattern of inhibin B secretion at the beginning of the metesterus and was associated with a significant decrease in inhibin B serum levels. This observation, following acute ovarian vascular occlusion, is probably due the effects of ischemia on hormonal regulation during the early follicular phase.