Effect of stress, metyrapone and adrenalectomy on compensatory ovarian hypertrophy.

Abstract

Subcutaneous injection of croton oil for stress or intraperitoneal injection of metyrapone was given to rats daily for 14 days after unilateral ovariectomy. Six-day adrenalectomized rats were unilaterally ovariectomized. The animals were sacrificed 15 days after unilateral ovariectomy. The weight of the ovary was expressed as that for 100g body weight.At this time, the remaining ovary of the unilaterally ovariectomized control increased significantly in weight. In contrast, no weight increase was found in the remaining ovary of the stressed unilaterally ovariectomized animal, which could, however, respond well with a weight increase to the small amount of HCG injected daily for 4days before autopsy. Consequently, these results indicate that the stress may decrease gonadotropin secretion, leading to suppressing compensatory ovarian hypertrophy.Metyrapone or adrenalectomy also abolished compensatory ovarian hypertrophy. Further, the remaining ovary of the same animals was shown to be able to take up preferentially 125I-labelled HCG on the day of autopsy. Therefore, metyrapone or adrenalectomy may also reduce gonadotropin secretion to inhibit compensatory ovarian hypertrophy.The mechanism involved in the stress, metyrapone or adrenalectomy-induced reduction of gonadotropin secretion was discussed.