Steroid Metabolism by the Canine Intestine

Abstract
Progesterone-4-14C placed in the small intestine of anaesthetized, heparinized dogs was found in the effluent venous plasma, first mainly as unchanged progesterone, then increasingly in the form of different metabolites. These include 5α-pregnanedione, 20β-hydroxypregn-4-en-3-one. 3β-hydroxy-5α-pregnan-20-one, 3α-hydroxy-5α-pregnan-20-one, at least one pregnancdiol epimer and a large group of polar metabolites. The share of sulphuric and/or glucuronic acid conjugates did not exceed two per cent of the total radioactivity.