The Mucification of the vaginal epithelium in rodents

Abstract

The mucosa of the vagina of small rodents undergoes during pregnancy and in some cases during pseudo-pregnancy a special transformation which results in complete mucification of the epithelium. This mucification was recorded in observations as far back as 1890 by Morau (1889), Lataste (1892), Retterer (1892 a, b ), and the descriptions of these authors caused important discussions on the structure of the vaginal epithelium. The study of this mucification was resumed when the vaginal cycle was considered in relation to the ovarian cycle (Long and Evans 1922; Selle 1922; Courrier 1924; Kelly 1929), and some of its cytological features were described by Florey (1932). The causation of the vaginal mucification was not thoroughly investigated until about 1930, when a number of workers postulated that the reaction was a specific and convenient test for the corpus luteum hormone (Harris and Newman 1931; Hisaw, Meyer and Weichert 1928; Wiesner and Patel 1929; Clauberg 1933). It was shown shortly afterwards however, that the mucification obtained with injections of corpus luteum extracts was probably dependent upon small amounts of oestrone contained in those extracts (Robson 1931; Meyer and Allen 1933; Fels 1934)- Desclin (1934) and Allen and Meyer (1935) later demonstrated that the effect seemed to be due to the inhibition of oestrone by progestin. I have shown (Klein 1935 a) that the maintenance of the mucification during pregnancy is due to the inhibition of the ovarian cycle by the placenta. Recently Selye, Browne and Collip (1936a) showed that combined administration of crystalline oestrone and progesterone to the adult ovariectomized rat produces mucification of the vaginal epithelium, while progesterone injected to the normally cyclic female rat does not (19366). It is clear from this short survey that the real causes of vaginal mucification are not yet satisfactorily known. In the present paper I give a report of experiments carried out on the golden hamster.