Abstract
Rat ovaries that have been made to function under the stimulus of the male pituitary as in the experiments of Goodman 1 (ovarian grafts), Witschi and Levine 2 (parabiosis) and Pfeiffer 3 (masculinized female pituitaries) have uniformly failed to become lutein-ized. The luteinizing hormone, however, has been shown to be present in small amounts in the pituitaries of normal male rats and abundant in those of castrated animals (Hellbaum and Greep 4 ). Cutuly, et al., 5 have shown that the pituitary of a castrated male stimulates the interstitial cells as well as the seminiferous tubules of a parabiotic hypophysectomized male partner. Furthermore, there is considerable experimental evidence for assuming that the luteinizing hormone is identical with the substance responsible for the internal secretory function of the male gonad. The available evidence then is contradictory in that the male pituitary appears to secrete luteinizing hormone if the end organ is a male gonad, and only follicle-stimulating hormone if the end organ is a female gonad.
The present experiments were devised to bring the entire reproductive systems of each sex under the simultaneous influence of a single male pituitary.
Male rats, aged 21 days, were gonadectomized and joined in parabiosis with 2 littermates—a male on one side and a female on the other. (See also Fig. 1 drawn like that of DuShane and others. 6 ) Four to 6 days later the 2 outside triplets were hypo-physectomized. Autopsies were performed 7 to 16 days after hypophysectomy. The gonads, sexual accessories, thyroids and adrenal glands were weighed and examined grossly. Vaginal smears were followed in some instances. The observations reported are based on 8 sets of triplet parabionts in which all except the central animal had been completely hypophysectomized.
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