Adrenalectomy: Effects on mating behavior,ovulation, and early gestation in the cycling rat

Adrenalectomy was performed 4 weeks prior to evaluating the effects on mating behavior, ovulation, and the first 10 days of gestation in 4-day cycling female rats. Mating behavior was essentially normal and occurred at times similar to sham-adrenalectomized animals on the afternoon of predicted proestrus. The number of ova ovulated was significantly reduced in mated adrenalectomized subjects in contrast to data reported by Rodgers (1971) for intact females mated at similar times in proestrus. Embryonic swellings were significantly fewer at day 10 of gestation than in the sham-adrenalectomized group providing additional evidence of reduced numbers of ova ovulated. Embryonic weights at day 10 of gestation were not affected by adrenalectomy. Removal of adrenocortical hormones significantly increased uterine weight on the morning of vaginal estrus. The data fail to show a significant delay in sexual receptivity as a result of removing adrenal progesterone, but suggest that adrenalectomy interferes with the neuroendocrine reflex mediating ovulation.