Corticosteroid 11 beta-hydroxysteroid dehydrogenase activities in vertebrate liver

In this paper, we examine corticosteroid 11 beta-oxidation and 11-reduction as properties of the microsomal 11 beta-hydroxysteroid dehydrogenase complex in vertebrate livers. No hepatic activity in the oxidative direction (11 beta -dehydrogenase) was found in the frog, toad, mud puppy, shark, and bird livers. In contrast, all mammalian livers had active oxidizing enzymes. Latency, defined as microsome-linked activity released by the detergent Triton DF-18, was a property of 11 beta-dehydrogenase in all mammalian livers. Mammal, bird, and dogfish livers reduced 11-dehydrocorticosteroids (11-reductase), while amphibians and bony fish did not. With the exception of rat liver, latency was a property of all the mammalian liver 11-reductases examined.