Effect of Injections of Urine from Pregnant Women on Ovary of the Rabbit.

Abstract

In the opinion of Marshall, the fact that the rabbit does not ovulate spontaneously, but only after coitus, and then at a definite time (10 hours) afterwards, “points to the conclusion that the follicles discharge in response to a stimulus conveyed to the ovary by its nerves.” 1 That the ovarian nerves are not indispensable is clear from the demonstration that ovulation may occur in the transplanted ovary. 2 Some humoral mechanism, therefore, may be safely assumed. The question arises, however, of the importance of this humoral mechanism. Is it, or is it not, a significant factor in the whole series of processes involved in ovulation in the normal rabbit? If it is of great significance, one should be able to provoke ovulation in the rabbit without coitus by injection of those substances which were responsible for the occurrence of ovulation in the transplants.

Stimulated by the recent work of Smith and Engle, 3 who were able to induce super-ovulation in the rat by the daily transplantation of fresh hypophyses, a series of rabbits were subjected to such transplantations, following exactly the technique of Smith and Engle. To date, it has been impossible to provoke ovulation in the rabbit by the transplantation of as many as 15 fresh rat hypophyses. Seeking for a more economical and more convenient source of the hormone of the anterior lobe, I was led to the use of urine from pregnant women by the reports of Zondek and Ascheim 4 in which it is stated that in such urine is found a substance whose biological effects closely simulate those of the anterior lobe of the hypophysis. In a series of female rabbits, in which a previous exploratory laparotomy had shown the presence of normal follicles and the absence of corpora lutea, the intraperitoneal injection of 12 cc. of urine from a pregnant woman, twice daily for 4 days, resulted in the appearance of fresh corpora lutea in the ovaries of each of the 7 rabbits so treated. Similar treatment of 9 rabbits with the urine of nonpregnant women was without effect.