11-BETA-HYDROXYSTEROID DEHYDROGENASE-ACTIVITY IN PROGESTERONE BIOTRANSFORMATION BY THE FILAMENTOUS FUNGUS COCHLIOBOLUS-LUNATUS

Progesterone biotransformation was examined in relation to hydroxylati ng and dehydrogenating enzymes of Cochliobolus lunatus. 11 beta-hydrox ysteroid dehydrogenase activity (11 beta-HSD) was located in cytosolic fraction and was NADP-dependent, inducible by progesterone and appare ntly unidirectional. Several inhibitors of 11 beta-hydroxysteroid dehy drogenase were tested; furosemide, glycyrrhizic-acid and carbenoxolone did not influence the dehydrogenation of 11 beta-hydroxy-4-pregnene-3 ,20-dione to 4-pregnene-3,11,20-trione, although grapefruit juice sign ificantly reduced the rate of progesterone hydroxylation. (C) 1997 Els evier Science Ltd. All rights reserved.