The effect of frozen ovarian autografts on compensatory ovulation and steroid production in unilaterally ovariectomized rats

Abstract

In the present study rats were unilaterally ovariectomized (ULO) and the surgically removed ovary was frozen for 13 days. After allowing the remaining ovary to compensate with respect to number of ova shed, the frozen graft was thawed and transplanted subcutaneously to determine the effect on ovulation number, cycle length, uterine weight, ovarian weight and plasma levels of estradiol-17beta (E2) and progesterone. Rats ULO at 45 days of age, which received an autograft 13 days later, had a decrease in the number of eggs shed as compared to control ULO rats (6.4 +/- 0.8 vs. 11.1 +/- 0.9 eggs, respectively) and a decrease in plasma E2 (14.5 +/- 1.7 VS. 21.0 +/- 1.5 PG/ML, respectively). No differences were observed in progesterone concentration, uterine weight, ovarian weight or cycle length. In contrast, rats ULO at 31 days of age, which received an autograft 13 days later, showed no differences in comparison to control ULO rats. Castrates which received ovarian autografts developed cycling vaginal smears and had increased E2 (31.9 +/- 4.3 pg/ml) and decreased progesterone (18.3 +/- 1.9 ng/ml) levels. Since ULO animals with autografts shed fewer ova, the present study demonstrates that the amount of ovarian tissue influences ovulation number either by utilization of gonadotropins or by an, as yet, undefined mechanism.

A study of ovarian autotransplantation without vascular a pedicle in rats

“…Callejo et al [25] showed that vaginal cytology of groups intraperitoneal and subcutaneous ovarian transplantations showed trophic maturation between days 4 and 10 after ovariectomy and insertion of the ovarian tissue implant, whereas the control group remained atrophic. In a study that was done with rats [26], at the first day of vaginal cornification after grafting, plasma estradiol-17 beta (45.8 + / − 4.0 pg/ml) was elevated in comparison to controls at metestrus (24.0 + / − 2.6 pg/ml), but plasma progesterone (21.5 + / − 4.0 ng/ml) was not different (30.6 + / − 1.7 ng/ml). Subsequently, at the first metestrus following grafting, plasma estradiol (23.0 + / − 3.5 pg/ml) was comparable to control values.…”