Conversion of 3β-Hydroxypregn-5-en-20-one to Progesterone by Transplantable Choriocarcinoma in Rats

Abstract

A transplantable tumor was induced by 7,12-dimethylbenz[a]anthracene in the uterus of a rat from which a fetus had been removed. Some rat tissues were incubated with ¹⁴C-3β-hydroxypregn-5-en-20-one in organ culture. ¹⁴C-progesterone was formed in the tumor and placenta as well as in the testes, ovaries, and adrenals, but none (or little) could be found in the liver, spleen, kidneys, and muscle. In addition, radioactive testosterone, 20α-hydroxypregn-4-en-3-one, and corticosterone were formed by the testes, ovaries, and adrenals, respectively. The data supported our morphologic finding that the tumor seemed to be derived from chorionic cells.