llβ-Hydroxysteroid Dehydrogenase of Lung and Testis

Abstract

Cortisol 11[beta]-hydroxysteroid dehydrogenase has been detected in rat lung and testes in amounts comparable to the levels found In the kidney of this species. The general properties of the activity in lung and testes are similar to the liver enzyme. NADP [nicotlnamlde adenine dinucleotide phosphate] is the preferred cofactor and the reaction is reversible. Cortisol, cortico sterone, 11[beta],17,21 -trihydroxy-5[alpha]-pregnane-3,20-dione and 11[beta]-hydroxy-[DELTA]4-androstene-3,17-dione are substrates but 11[beta],17,21 -trihydroxy-50-pregnane-3,20-dione is not attacked. Similar levels of activity were found in mouse lung and rabbit testes but, under the same conditions, no activity could be detected in beef, pig or sheep lungs and testes.