HISTOCHEMICAL UTILIZATION OF 3α-, 6β-, 11α-, 12α-, 16α-, 16β-, 17α-, 21- AND 24-HYDROXYSTEROIDS

Abstract

SUMMARY The histochemical utilization of 3α-, 6β-, 11α-, 12α-, 16α-, 16β-, 17α-, 21- and 24-hydroxysteroids in human and mouse testis, human placenta, mouse ovary and rat adrenal has been investigated using a coupling method and the tetrazolium salt, Nitro-BT. 3α-Hydroxysteroid dehydrogenase was present in the human Leydig cells and placental syntrophoblast, but there was little in rat adrenal zona fasciculata and in mouse ovary; the enzyme is NAD or NADP dependent. 6β-Hydroxysteroid dehydrogenase was present in human Leydig cells, mouse Leydig cells, placental syntrophoblast, ova, granulosa, theca interna, corpora lutea and interstitial tissue; it is NAD dependent. 11α-Hydroxysteroid dehydrogenase activity was very poorly developed, being NAD dependent and demonstrable only in human Leydig cells. 12α-Hydroxysteroid dehydrogenase could be demonstrated in some human Leydig cells; it was both NAD and NADP dependent. 16α-Hydroxysteroids were very poorly used by all the tissues surveyed. 16β-Hydroxysteroids gave an intense histochemical reaction with NAD in human Leydig and Sertoli cells, in placental trophoblast, in adrenal zonae glomerulosa, fasciculata and reticularis and in all ovarian tissues. 17α-, 21- and 24-hydroxysteroids were poorly utilized by human Leydig cells, but not by the other tissues. The first two were NAD dependent; 24-hydroxysteroid utilization was both NAD and NADP dependent. The techniques used are believed to demonstrate specific hydroxysteroid dehydrogenases because of variations in pyridine nucleotide requirement and in the location in the tissues of different hydroxysteroid dehydrogenases. Moreover, stereoisomers of the same hydroxysteroid behave differently in this system. The role of steroid 5α- and 5β-dehydrogenases is discussed in connexion with the histochemical results.