3β-Hydroxysteroid DEHYDROGENASE IN THE ADRENAL GLAND AND PLACENTA

Self Cite

The ability of cells from the zona fasciculata and zona reticularis of the horse adrenal cortex to transform [7\g=a\-3H]pregnenolone, [4-14C]progesterone, [7\g=a\-3H]17\g=a\-hydroxypregnenolone and [4-14C]17\g=a\-hydroxyprogesterone to cortisol in vitro was investigated.It was found that: (1) Both types of cell form cortisol from these steroids.(2) The transformation is greater in fascicular cells. (3) The formation of 17\g=a\-hydroxyprogesterone from pregnenolone (via either progesterone or 17\g=a\-hydroxypregnenolone) is slower that the subsequent formation of cortisol from 17\g=a\-hydroxyprogesterone.(4) The formation of 17\g=a\-hydroxyprogesterone from 17\g=a\-hydroxypregnenolone is rate-limiting in cortisol formation, but is about 2\m=.\4times faster in fascicular than in reticular cells.(5) 17\g=a\-Hydroxylation of progesterone is also faster in fascicular than in reticular cells.

Section: Discussionmentioning

confidence: 69%

Biochemistry of Histologically Defined Zones in the Adrenal Cortex: Cortisol Synthesis in the Horse

Cameron¹,

Grant²

1967

Self Cite

“…A variety of other substrates have been shown to be satisfactory for the histochemical localization of this reaction (Baillie, Cameron, Griffiths & Hart, 1965) which, in normal human adrenal glands, appears to be confined to the zona fasciculata. The 3a-, 11a-and 21-hydroxysteroid dehydrogenases demonstrated in the rat adrenal have the same zonal location as the 3/?-hydroxysteroid dehydrogenase ; 6/?-hydroxysteroid dehydrogenase activity differs from the foregoing enzymes in that it is found in the zona reticularis as well as in the zona fasciculata.…”

Section: Histochemical Considerationsmentioning

confidence: 99%

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

Baillie¹,

Calman²,

Ferguson³

et al. 1966

Self Cite

The histochemical utilization of 3\g=a\-,6\g=b\-, 1 1 \ g = a \ -,12\g=a\-,16\g=a\-,16\g=b\-,17\g=a\-, 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. 3\g=a\-Hydroxysteroiddehydrogenase 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. 6\g=b\-Hydroxysteroiddehydrogenase was present in human Leydig cells, mouse Leydig cells, placental syntrophoblast, ova, granulosa, theca interna, corpora lutea and interstitial tissue; it is NAD dependent. 11\g=a\-Hydroxysteroiddehydrogenase activity was very poorly developed, being NAD dependent and demonstrable only in human Leydig cells. 12\g=a\-Hydroxysteroiddehydrogenase could be demonstrated in some human Leydig cells; it was both NAD and NADP dependent. 16\g=a\-Hydroxysteroids were very poorly used by all the tissues surveyed. 16\g=b\-Hydroxysteroidsgave 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. 17\g=a\-, 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 5\g=a\-and 5\g=b\-dehydrogenases is discussed in connexion with the histochemical results.

“…The most striking feature of our results in the adrenals of Cushing's syndrome is the change in zonation of the 3/?-hydroxysteroid dehydrogenase. Previous investi¬ gation (Baillie, Cameron et al 1965 normal adrenal this enzyme could be detected histochemically mainly in the zona fasciculata. In Cushing's disease, however, the enzyme was present in all zones, except the inner part of the zona fasciculata.…”

Section: Discussionmentioning

confidence: 78%

“…The original view of Symington (1962), that the zona fasciculata is principally a storage zone, may therefore be true for the inner part of the zone. Secondly, of the enzymes described, only the 3/?-hydroxysteroid dehydrogenase, the activity of which has been previously described in detail in the human adrenal (Baillie, Cameron, Griffiths & Hart, 1965), is concerned in a biosynthetic pathway. The remaining enzymes then are in many cases of doubtful physiological significance, especially regarding the biosynthesis of steroid hormones.…”

Section: Discussionmentioning

confidence: 99%

Hydroxysteroid Dehydrogenases in the Human Adrenal Cortex

Calman¹,

Baillie²,

Ferguson³

et al. 1966

Self Cite

The histochemical utilization of 3\g=a\-,3\g=b\-,6\g=b\-,11\g=a\-,11\g=b\-,12\g=a\-,16\g=a\-,16\g=b\-, 17\g=a\-,17\g=b\-,20\g=a\-, 21-and 24-hydroxysteroids by three normal adult human adrenal glands, two human foetal adrenal glands, three adrenals from patients with Cushing's syndrome and one adrenal adenoma are described.The normal adult human adrenal showed high 16\g=b\-hydroxysteroid dehydrogenase activity in the zona glomerulosa. Activity restricted to the outer part of the zona fasciculata was recorded with 3\g=a\-,3\g=b\-,6\g=b\-, 11\g=b\-, 16\g=a\-,16\g=b\-, and 17\g=b\-hydroxysteroids. The zona reticularis utilized 3\g=a\-,3\g=b\-, 11\g=b\-,16\g=b\-and 17\g=b\-hydroxysteroids less well than the zona fasciculata.The adrenals of Cushing's syndrome showed activity only for 3\g=b\-and 16\g=b\-hydroxysteroiddehydrogenases; this activity was noted in all three zones. The activity pattern of the adrenal adenoma resembled that of the normal adult human adrenal except that greater activity for 16\g=a\-hydroxysteroid dehydrogenase was noted.The foetal part of the human foetal cortex was extremely active, showing 3\g=a\-,3\g=b\-,6\g=b\-,11\g=b\-,12\g=a\-,16\g=a\-,16\g=b\-,17\g=b\-,20\g=b\-and 21-hydroxysteroid dehydrogenase activity. The definitive cortex behaved similarly to the adult gland and possessed 3\g=a\-,3\g=b\-,11\g=b\-,16\g=b\-and 17\g=b\-hydroxysteroid dehydrogenases; some evidence of zoning of the definitive cortex was seen with the 16\g=b\-hydroxysteroid.The relevance of these findings in the light of current knowledge of adrenal zonation is discussed.