Plasma estradiol-17beta, progesterone, FSH, LH and follicular development in castrated female rats with subcutaneous ovarian autografts.

Abstract

Castrated adult female rats with subcutaneous ovarian autografts were killed at 3-day intervals for 30 days after grafting. Plasma estradioI-17� (E2), progesterone (P), FSH, and LH values were determined by radioimmunoassay, and follicular development was evaluated histologically. Eighty-two percent of all animals developed cycling vaginal smears by 7.9± 0.5 days after receiving the autografts. Cycle lengths were 4 or 5 days in 76 percent of the animals and 6 days in20 percent. There was no decrease in the number of follicles>150 urn per graft up to 30 days after grafting. However, there were more follicles>150 �rn at proestrus (17.1 ± 1.0) than either metestrus (3.2 ± 1.1) or estrus (3.3 ± 1.1). Corpora lutes (CL) were formed by luteinization of intact follicles. Plasma E2, P, and uterine weight in this model were not different from the intact rat. E2 peaked at 18 days after grafting (88 ± 17 pg/ml), and then gradually decreased until Day 30 (23 ± 7 pg/mI). P reached a plateau at 15 days after grafting (41 ± 7 nglml) and did not change for the remainder of the experiment.On Days 3,6,12 and 15, FSH levels were comparable to castrate values. FSH decreased from Day 15 (1012 ± 178 ng/ml) until Day 27(359 ± 71 ng/ml) but never decreased to diestrous values in the intact rat. The standard errors of the means of LH were large, and LH only decreased significantly below castrate levels on Day 27 (59 ± 14 ng/mI). Analysis of the data accordingto day of estrous cycle at autopsy, showed thatE2, P, and FSH didnotvaryat proestrus, estrus, or metestrus. However, there was asurgeof LH (2393 ± 741 ng/ml) atproestrus. In order to study the effectof the time the graftwas placedrelativeto pubertyon graft function, female rats were castrated and received ovarian autografts before (Group 1) or after (Group 2)puberty. Grafts werepresentforthesame length of time in both groups but the grafts in ratsinGroup 2 were exposedtopostpubertalgonadotropinslongerthan grafts in rats in Group 1 were.There was no difference in E2 between Groups 1 and 2 (35.7 ± 3.6vs.33.1 ± 4.1 pg/mI), but P was decreasedinGroup 2 (28.3 ± 1.6 vs. 15.2 ± 2.0 ng/ml). These data show that ovarian autografts in castrated female rats function like intact, in situ ovaries in many respects. The grafts produce E2 and P which suppress pituitary gonadotropins