The effect of oestrone on normal and castrated male rats

IT is now established that male and female hormones are produced in both sexes.In the urine of man and non-pregnant woman they are often excreted in approximately equal amounts [Dingemanse, 1931; Womack and Koch, 1932; Freud, 1933].Zondek [1934] obtained the largest amount of oestrin from the urine of stallions, in which he found 170,000 M.U. per litre; while he obtained 200 M.U.from the non-pregnant and 100,000 M.U.from the pregnant mare; and from 30 to 200 M.U. in sexually mature woman and 10,000 M.U. in pregnant woman.Zondek and Euler [1934] suggest that in the organism oestrin is produced in the gonads, in the placenta and probably in some other tissues, since Loewe et al. [1932] found small amounts of oestrin even in the urine of castrated animals.These facts make necessary a careful examination of the influence of oestrin on males.That oestrin had a physiological influence on young castrated rats was shown by Freud [1933].Both oestrone and oestriol promoted the development of smooth muscle in the seminal vesicles of such rats and increased the influence of testicular hormone on the seminal vesicles.That oestrin has a pathological influence has also been demonstrated.Thus Moore and Price [1932] injected 10-15 rat units of oestrin for 20 days into adult male rats and obtained a marked decrease in size of the testes, seminal vesicles and prostate, the atrophy of these last two organs sometimes being equal to that in castrates.Simultaneous injection of gonad-stimulating, or testicular hormone, however, prevented the injurious effect of oestrin (except the testicular damage which was not prevented when testicular hormone was used).In castrated male rats no effect was produced by injections for 20 days of oestrin alone (12-40 R.I.), or in doses of 12 R.U. combined with 6 c.u. of testicular hormone.Lacassagne [1933] used young, adult and castrated mice injected for different periods with about 500 M.U. per week of oestrin.During the first 2 weeks atrophy of the seminal vesicles and prostate were noted, but later a pathological enlargement of the posterior lobe of the prostate developed, with stratification and keratinisation of the epithelium.These changes were usually observed after treatment for 3 months.Burrows and Kennaway [1934] painted the skin of mice twice a week, for 6-22 weeks, with a soiution of oestrin in a dose of about 125 R.U.The following changes were obtained in male mice; scrotal hernia, atrophy of the testes and seminal vesicles, enlargement of the posterior lobe of the prostate with histological changes similar to those observed by Lacassagne, and even in some cases resembling those in tumours.These pathological changes indicate the need for caution in following the suggestion of Freud [1933] that oestrin should be used in clinical practice in males.