Effect of Theelin on Immature Guinea Pigs

Abstract

It was previously pointed out that the vaginal smears of rabbits were not reliable as an index of hormonal activity, confirming the work of Kunde and Proud. 1 A more careful search of the literature reveals that Courrier 2 had previously observed that there was no histological change in the vaginal mucosa of several rabbits either during heat or after the administration of an ovarian extract.

We also reported an observation in 3 immature guinea pigs of the opening of the vulval orifice 48 hours after injection with the urine of a pregnant woman. To Courrier 3 again belongs the credit of having made the same observation in a single guinea pig that he injected with an ovarian extract. Laqueur 4 in studying the uterine hypertrophy of rodents after injection with an ovarian hormone, also noted the vulval opening in 2 guinea pigs but observed that one of his controls also had a wide open vagina at the end of the experimental period, namely a week. In trying to repeat our original phenomenon we found that it is not constant, appearing in but 2 of 23 animals injected with theelin-bearing fluids, while in 2 out of 34 guinea pigs the opening of the vulva, without, however, typical oestrus smears, appeared spontaneously.

Our attention was shifted, therefore, from the vulva to the effect of theelin on the uterus. Hypertrophy of the genital tract in immature animals in general is described as characteristic of the follicle hormone. Mice, rats, rabbits, and dogs, have been extensively investigated. But other than the two authors referred to above and Frank, 5 little seems to have been published. Jares 6 showed that guinea pigs are incapable of giving the Aschheim-Zondek reaction, although Papanicolaou 7 has recently demonstrated microscopic changes in the follicle following the injection into immature guinea pigs of the urine of pregnant cows.