Richard I. Pencharz

Ineffectiveness of Prolan in Hypophysectomized Animals.

A complete hypophysectomy with cautery at the base of the brain was done by Frederick L. Reichert on a female collie (hybrid) puppy 7 weeks of age from a litter where fortunately we had a sister control. Every 2 weeks, weighings and radiographs of the leg and skull were taken. After 2 such periods it was evident that the hypophysectomy was complete. Six months after the operation daily administration of Prolan was begun and continued for 53 days. An average of 30 cc. was given daily. At this juncture an ovary and one uterine horn were removed and sectioned. The naked eye impression of infantilism in the genitalia was verified. The animal was allowed to rest for 2 weeks. For a month thereafter about 15 cc. daily of a more potent preparation of Prolan was administered. This was proven to contain 80 to 100 rat units per cc. Death from a pneumonia at this juncture terminated the experiment but examination of the remaining ovary and uterine horn showed essentially the same conditions as were previously found, i. e., a persisting true infantilism. Two other puppies were totally hypophysectomized at 6 weeks of age and subsequently similarly treated with Prolan—one of them a year after the operation and hence open to the objection that an irretrievable recession and fibrosis of the ovaries had resulted before treatment. The second puppy was hence treated 2 months after the operation but in spite of prolonged high dosage with Prolan the results were completely negative as in the first case reported.

Reactions of Mammary Glands of Normal and Hypophysectomized Male Guinea Pigs to Female Sex Hormone

It has become increasingly important during these last few years of intensive experimentation on the hormonal control of the mammary apparatus to discriminate between the respective rôles played by the primary female sex hormone (estrin) and the anterior pituitary mammary-stimulating hormone (mammatropin), in inducing growth and secretory activity of the breast. Several years ago in the course of experiments on the effects of purified gonadotropic hormone in hypophysectomized rats 1 it was noticed that although the female genital tract responded to the hormones of the stimulated ovaries, the mammary apparatus showed only a poorly-developed duct system. These findings pointed to a greater importance of the anterior pituitary as a source of a mammary growth-promoting factor than is admitted by some investigators. To further determine the degree of mammary stimulation possible through estrin, it was decided to use hypophysectomized male guinea pigs, since Laqueur and others 2 have shown that the intact male guinea pig responds to estrin treatment by mammary growth and lactation. Asdell and Seidenstein 3 found the development of the mammary glands of ovariectomized, hypophysectomized rabbits injected daily for 15 days with 25 rat units of estrin plus 4 rabbit units of progestin almost the same as ovariectomized, non-hypophysectomized rabbits similarly treated. Apparently they did not study the effect of estrin alone.

Induced Postpartum Lactation in Hypophysectomized Rats.

Summary It was possible to induce postpartum lactation in hypophysectomized rats, and to maintain a functional development of their mammary glands by injections of combined mammotropic and adrenocorticotropic hormones. That this treament did not constitute complete substitution therapy was shown, however, by the fact that sufficient milk was not available for sustenance of the young.

Gonadotropic Effects in Hypophysectomized Female Rats of Implants of Pituitaries from Castrated Males

Studies of female rats united parabiotically with castrated males have shown that they are characterized by constant estrus and that their ovaries contain only large follicles (Witschi and others). The phenomenon appears to establish the actual secretion into the blood stream of the follicle stimulating hormone only on the part of the pituitary of the castrated male parabiont. The present study shows that the pituitaries of such castrated males nevertheless contain or “house” appreciable amounts of luteinizing hormone. Young mature males were castrated and after 40 days their pituitaries were implanted into hypophysectomized females 26 days of age. While a dose level was found in which follicles only occurred in the ovaries of the hypophysectomized recipients, double this dose (4 glands) led to the appearance of corpora lutea. Implants of the hypophyses from normal litter brothers produced only follicles at both dose levels. Parallel experiments with normal recipients showed that corpora were produced by both levels of castrate and normal hypophyses. The luteinizing effect of castrate male hypophysis as tested by implantation, therefore, contrasts with the results obtained by parabiosis. The explanation offered for the difference is that the absorption of the implant frees the factor responsible for luteinization, whereas this substance is retained in vivo by the hypophysis of the parabiont.