AJP - Renal Physiology, Vol 261, Issue 4 706-F719, Copyright © 1991 by American Physiological Society

ARTICLES

Ca2+ channels and aldosterone secretion: modulation by K+ and atrial natriuretic peptide

P. Q. Barrett, C. M. Isales, W. B. Bollag and R. T. McCarthy
Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510.

Two populations of voltage-dependent Ca2+ channels, T-type and L-type, are present in bovine adrenal glomerulosa cells. Activation of these channels by cell depolarization with the resultant increase in Ca2+ influx may be one way in which agonists regulate aldosterone secretion. In addition, these channels may be the site of antagonist action. In the present study, we have demonstrated that atrial natriuretic peptide (ANP), an antagonist of aldosterone secretion, alters only the voltage dependence of inactivation of the T-type channel while enhancing the voltage dependence of activation of a subpopulation of L-type channels. These patch-clamp data, which demonstrated contrasting effects of ANP on the activity of T- and L-type Ca2+ channels correlated with changes induced in cytosolic calcium [( Ca2+]i). In the weakly depolarized cell, ANP (greater than 30 pM) lowered [Ca2+]i, in contrast to the strongly depolarized cell, in which ANP (greater than 10 pM) raised [Ca2+]i. Similar alterations in the level of [Ca2+]i in the stimulated cell were induced by the Ca(2+)-channel blocker nitrendipine and the L-type channel agonist, (-)BAY K 8644. With increasing concentrations of extracellular K+ (3.5-60 mM) the rate of aldosterone secretion rose nonmonotonically. ANP inhibited secretion over this broad range of K+ concentrations; however, its potency as an inhibitor of secretion was diminished in the strongly depolarized cell. These data are discussed in the context of a model that proposes a role for sustained Ca2+ influx in cell activation.

This article has been cited by other articles:

				M. D. Payet, T. L. Goodfriend, L. Bilodeau, C. Mackendale, L. Chouinard, and N. Gallo-Payet An oxidized metabolite of linoleic acid increases intracellular calcium in rat adrenal glomerulosa cells Am J Physiol Endocrinol Metab, December 1, 2006; 291(6): E1160 - E1167. [Abstract] [Full Text] [PDF]

				A. SPAT and L. HUNYADY Control of Aldosterone Secretion: A Model for Convergence in Cellular Signaling Pathways Physiol Rev, April 1, 2004; 84(2): 489 - 539. [Abstract] [Full Text] [PDF]

				E. Perez-Reyes Molecular Physiology of Low-Voltage-Activated T-type Calcium Channels Physiol Rev, January 1, 2003; 83(1): 117 - 161. [Abstract] [Full Text] [PDF]

				M. Simaan, S. Picard, J. St-Louis, and M. Brochu Functional alteration of dihydropyridine-sensitive Ca2+ channels in the adrenal glomerulosa of pregnant rats Am J Physiol Endocrinol Metab, May 1, 2000; 278(5): E925 - E932. [Abstract] [Full Text] [PDF]

				A. D. Maturana, A. J. Casal, N. Demaurex, M. B. Vallotton, A. M. Capponi, and M. F. Rossier Angiotensin II Negatively Modulates L-type Calcium Channels through a Pertussis Toxin-sensitive G Protein in Adrenal Glomerulosa Cells J. Biol. Chem., July 9, 1999; 274(28): 19943 - 19948. [Abstract] [Full Text] [PDF]

				X.-L. Chen, D. A. Bayliss, R. J. Fern, and P. Q. Barrett A role for T-type Ca2+ channels in the synergistic control of aldosterone production by ANG II and K+ Am J Physiol Renal Physiol, May 1, 1999; 276(5): F674 - F683. [Abstract] [Full Text] [PDF]

				M. F. Rossier, E. A. Ertel, M. B. Vallotton, and A. M. Capponi Inhibitory Action of Mibefradil on Calcium Signaling and Aldosterone Synthesis in Bovine Adrenal Glomerulosa Cells J. Pharmacol. Exp. Ther., December 1, 1998; 287(3): 824 - 831. [Abstract] [Full Text]

				S. Kanwal, B. J. Elmquist, and G. J. Trachte Atrial Natriuretic Peptide Inhibits Evoked Catecholamine Release by Altering Sensitivity to Calcium J. Pharmacol. Exp. Ther., November 1, 1997; 283(2): 426 - 433. [Abstract] [Full Text]

				N. Cherradi, M. F. Rossier, M. B. Vallotton, and A. M. Capponi Calcium Stimulates Intramitochondrial Cholesterol Transfer in Bovine Adrenal Glomerulosa Cells J. Biol. Chem., October 18, 1996; 271(42): 25971 - 25975. [Abstract] [Full Text] [PDF]

				M. T. Kailasam, R. J. Parmer, J. H. Cervenka, R. A. Wu, M. G. Ziegler, B. P. Kennedy, I. A. Adegbile, and D. T. O'Connor Divergent Effects of Dihydropyridine and Phenylalkylamine Calcium Channel Antagonist Classes on Autonomic Function in Human Hypertension Hypertension, July 1, 1995; 26(1): 143 - 149. [Abstract] [Full Text]