TESTOSTERONE AND OESTRADIOL IN DOGS WITH TESTICULAR TUMOURS

Abstract

ABSTRACT The mean peripheral plasma concentration of oestradiol was found to be increased in 3 dogs with Sertoli cell tumours and in 3 dogs with seminomas, whereas the plasma testosterone showed no difference as compared to a group of dogs without testicular neoplasia. In two thirds of the cases the concentration of oestradiol in the spermatic venous blood draining the neoplastic testes was clearly higher than in the normal dogs. The testosterone concentration in the spermatic venous blood from the tumour bearing testes was lower than in the spermatic venous blood of the contralateral partner testes in the same dogs, though not different from the spermatic venous concentration in the control dogs. There was no correlation between the presence or absence of signs of feminization and the peripheral or spermatic venous concentration of sex steroids. It is concluded that not only Sertoli cell tumours, but also seminomas can secrete increased amounts of oestrogens. This is possibly due to the presence of a larger than normal mass of tissue capable of converting testosterone, or its precursors, to oestradiol.