ACTIVITY OF 5-ALPHA-REDUCTASE AND 17-BETA-HYDROXYSTEROID DEHYDROGENASE IN THE INFRAINFUNDIBULUM OF SUBJECTS WITH AND WITHOUT ACNE-VULGARIS

Linoleic acid deficiency, interleukin 1, retinoids and androgens have been implicated as causative factors in the follicular hyperkeratiniza tion seen in acne. The goal of this study was to test the hypothesis t hat more androgens are produced in follicles of acne subjects compared to subjects without acne. Thirty-four subjects (males and females wit h and without acne) were studied. The activity of 5 alpha-reductase (5 alpha-R) and 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) was d etermined in keratinocytes cultured from the infrainfundibulum and epi dermis. Mean enzyme activities were slightly higher in the acne groups compared to the groups without acne, but differences were not statist ically significant, perhaps due to limitations of this in vitro model. The activity of both 5 alpha-R and 17 beta-HSD was significantly grea ter in infrainfundibular keratinocytes compared to epidermal keratinoc ytes in all subject groups. 17 beta-HSD activity was 2.5- to 7-fold gr eater than the activity of 5 alpha-R in infrainfundibular keratinocyte s. The regulation of 17 beta-HSD by endogenous factors may be importan t in determining the directional activity of 17 beta-HSD and hence the local concentration of testosterone within the infrainfundibulum. Add itional studies of the effects of androgens on follicular keratinizati on are needed.