Uterine Bleeding of the Interval Type in Macacus Monkey During Injections of Extracts of Pregnancy Urine. ∗

Abstract

Uterine bleeding in the spayed or immature macacus monkey is known to occur from an interval type endometrium about 6 days after cessation of an adequate treatment with oestrin (Theelin, Allen 1 , Maddux 2 ;) (Amniotin, Morrell et al. 3 ). These observations have been repeatedly confirmed in this laboratory. Uterine bleeding in the adult also occurs after bilateral ovariectomy (Allen; Van Wagenen and Aberle 4 ) or occasionally after unilateral ovariectomy (VanWagenen and Aberle). (Uterine bleeding indicates a hemorrhage of uterine origin macroscopically visible on the external genitalia of the monkey, but which may not be homologous with menstruation). Saiki 5 has shown that uterine bleeding may be induced in immature macaques 4 to 9 days after the cessation of 8-17 days treatment with an extract of anterior lobe (P. D. & Co.). Our work confirms these results. However, if water soluble extract of pregnancy urine or the “luteinizing hormone” (P. D. & Co.) be administered in adequate doses for from 19 to 22 days, in 2.8 to 4 kg. animals, bleeding occurs during the course of treatment. If the injections are continued, bleeding stops in 4 to 6 days, after an apparently normal flow.

Injections of extracts of pregnancy urine have failed to cause reddening of the sexual skin, or induce the turgose, pachydermatous condition of the circumgenital and anal area which is obtained by injections of oestrin or is seen after ovarian stimulation by means of water soluble fraction of pyridine extract (Hisaw, Fevold and Leonard 6 ). No follicular cysts, nor any determinable growth of the ovarian follicle occurs after such injections. Modification of the structure of large atretic follicles may be obtained after continued intravenous injection of pregnancy urine, but no structures which are clearly corpora lutea have as yet been obtained with this substance, although luteinization in the rat is a pronounced result after prolonged subcutaneous intraperitoneal or intravascular injections.