AJP - Endocrinology and Metabolism, Vol 256, Issue 4 E475-E482, Copyright © 1989 by American Physiological Society
Potassium-induced aldosterone biosynthesis in cultured rat zona glomerulosa cells
J. Muller, M. Lauber and C. Schmid
Department of Medicine, University Hospital, Zurich, Switzerland.
Rat adrenal zona glomerulosa cells lost their ability to produce
aldosterone from either endogenous precursors or added deoxycorticosterone
within 2 days of primary monolayer culture in a medium with a potassium
concentration of 6.3 mmol/l. The lost corticosterone methyl oxidase I and
II activities were totally regenerated when the ambient potassium
concentrations was raised to 31 mmol/l. The conversions of
deoxycorticosterone to 18-hydroxycorticosterone and aldosterone were
completely restored by culture in a high-potassium medium also in zona
glomerulosa cells of rats in which aldosterone biosynthesis had been
suppressed by potassium restriction and sodium loading. However, these
conversions were not induced in zona fasciculata-reticularis cells. The
induction of aldosterone biosynthesis was associated with the appearance of
a mitochondrial 49,000 protein cross-reacting with an antibody raised
against bovine adrenal cytochrome P-450(11) beta. Thus primary cultures of
zona glomerulosa cells are promising models for studying in vitro the
molecular mechanisms of long-term adaptation of aldosterone biosynthesis to
sodium and potassium intake.
