Edward L. Schwabe

Progesterone in Adrenalectomized Rats

Summary Our results confirm previous reports that progesterone will keep adrenalectomized rats alive. 1 , 2 , 12 In our colony, after 2-stage adrenalectomy, doses of one milligram daily or less were usually adequate to keep young, newly-weaned, female rats alive and showing some gain in weight throughout the treatment period.

Duration of Estrus in Ovariectomized and Adrenal-Ovariectomized Rats Before and After Theelin

Within the last few years numerous papers have appeared on several phases of the adrenal problem without adding, as Rogoff 1 has recently discussed, any very definite contribution. The literature on the sex-relationship has been especially confusing; and the many references cited by Kroc and Martin 2 indicate that total adrenalectomy may cause no change, a slight modification or complete inhibition of the estrus cycles. These authors made a point of the fact that the weight-loss of adrenalectomized rats must be restored before normal estrus is again established following injections of the cortical hormone. Yet this same result, as to normal estrus in adrenalectomized rats, may be obtained by allowing the animals to drink salt solutions (Kutz, et al. 3 ). This led us to study, by a different procedure, the theelin-inhibition problem previously reported. 4 The present approach has been first, to compare ovariectomized and adrenal-ovariectomized rats as to the estrus occurring on successive days following the operation; and second, the duration and reoccurrence of estrus that followed various doses of theelin. The estrus cycles were taken daily, by the pipette method, for 2 weeks or longer preceding and following the operation. Six to 10 days following the operation, all rats were placed on Ringers solution as their only source of drinking water. A few animals died before the sixth day; but these are not considered in the data. All animals were autopsied. In 4 of the 60 rats composing the adrenal-ovariectomized group, adrenal fragments were found. Ovarian fragments were not seen in either group. The per cent of rats in estrus each day for 10 days before and 12 days after ovariectomy (group O) is shown in Fig. 1; and similar results for adrenal-ovariectomized rats (group A-O) are found in Fig. 2. The 2 figures are almost identical in every way.

THE RESPONSE OF THE OVARIES TO GONADOTROPIC EXTRACTS IN SPLENECTOMIZED RATS

THE REFRACTORY state or antihormone condition induced in animals after prolonged treatment with pituitary extract is apparently not well understood. Selye, et al.1 induced a refractory state in rats by giving frequent implants of rat pituitaries. KatZ man, et al.2 were not able to confirm these findings in regard to pituitary implants from rats inducing antihormones in recipient rats. Still others, Thompson,3 Thompson and Cushing4 and Rowlands,5 were able to show that the anti-substance is not specific in that antiserum from one animal inactivated pituitary gonadotropic hormone from several species of animals. Gordon6 has given considerable evidence to show that the spleen is important in the forma tion of the antihormone. On the other hand pituitary glands from castrated rats implanted into young rats gave large ovaries of approximately equal weight in both splenectomized and in normal rats.7,8 The present report deals with gonadotropic extracts in splenectomized rats. Methods. Young rats approximately 3...