Two forms of cytochrome P-450(11 beta) in rat zona glomerulosa cells: a short review.
Aldosterone, the major mineralocorticoid hormone, is produced exclusively in the zona glomerulosa of the mammalian adrenal cortex. In the rat species, this zonal specificity of aldosterone biosynthesis appears to be due mainly to the existence of a second form of cytochrome P-450(11 beta), which differs from the major form of the enzyme (molecular weight 51,000) by (1) a lower molecular weight (49,000), (2) a broader range of catalytic activities, which include corticosterone methyl oxidation 1 and 2, (3) an exclusive occurrence in the zona glomerulosa, and (4) a crucial dependence on sodium and potassium intake. The 49K form of the enzyme can be induced by potassium ions in vivo (potassium repletion of potassium-deficient rats) or in vitro (primary cell culture). The biosynthesis of this protein is controlled most likely at the level of transcription. According to indirect evidence, ACTH induces only the 51K form of the enzyme in vitro. Prolonged treatment of rats with a high dose of ACTH has a repressive effect on the 49K form of the enzyme.
Müller
J
J
Department of Medicine, University Hospital, Zürich, Switzerland.
Schmid
C
C
Böni-Schnetzler
M
M
Lauber
M
M
D000818:Animals; D002478:Cells, Cultured; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis*; D007527:Isoenzymes / Q000032:analysis*; D008970:Molecular Weight; D051381:Rats; D013252:Steroid 11-beta-Hydroxylase / Q000032:analysis / Q000378:metabolism*; D015384:Zona Glomerulosa / Q000166:cytology* / Q000201:enzymology
D007527:Isoenzymes; D003577:Cytochrome P-450 Enzyme System; D013252:Steroid 11-beta-Hydroxylase