Steroid metabolism in the rabbit. Biliary and urinary excretion of metabolites of [4-14C]testosterone

Abstract

[4-l4C]Testosterone was administered to anesthetized male and female New Zealand White rabbits as a single injection or as a 45-60 min. infusion. After a single dose a total of approx. 56-80% of the radioactivyt was excreted in bile and urine. After infusion total recovery of radioactivity was approx. 63-75%. The mean ratio of metabolites in urine to those in bile was 0.77 [plus or minus] 0.41 (range 0.3-1.5). Bile and urine samples were hydrolysed successively by [beta]-glucuronidase, cold acid and hot acid. In both bile and urine neutral metabolites extracted by ethyl acetate-ether were found mainly after [beta]-glucuronidase hydrolysis, but a considerable proportion of the dose was converted into substances not extractable from alkaline aqueous solution after all forms of hydrolysis used.