![]() ![]() Both cytochrome P-450 cDNAs have been cloned and expressed in non-steroidogenic cells, but only one is expressed in the zona glomerulosa and only this glomerulosal cytochrome P450 can further hydroxylate deoxycorticosterone to generate aldosterone. Two distinct cytochrome P-450 cDNAs which hydroxylate deoxycorticosterone at the 11 beta position have been described in the rat, human and mouse. Rat zona fasciculata cells in primary culture under similar conditions did not synthesize aldosterone, suggesting that the regulation of the expression of the enzymes responsible for the biosynthesis of aldosterone in the two species is different. Calf zona glomerulosa and fasciculata cells both responded well to ACTH and angiotensin II, but the zona fasciculata cells respond very poorly compared to glomerulosa cells to increased potassium in the media. ![]() In the presence of these additives, calf zona fasciculata cells in primary culture synthesize aldosterone at rates which can approach those from cells isolated from the zona glomerulosa. Calf zona glomerulosa cells rapidly lose the ability to synthesize aldosterone when placed in primary culture unless they are incubated in the presence of the antioxidants butylated hydroxyanisol and selenous acid, the radioprotectant DMSO, and the cytochrome P-450 inhibitor metyrapone. ![]() The glucocorticoids cortisol and corticosterone, depending upon the species, are synthesized in the inner cortex, the zona fasciculata. Aldosterone production occurs in the outer area of the adrenal cortex, the zona glomerulosa. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |