AJP - Cell Physiology, Vol 267, Issue 5 C1239-C1245, Copyright © 1994 by American Physiological Society

ARTICLES

Angiotensin II-dependent proximal tubule sodium transport is mediated by cAMP modulation of phospholipase C

J. R. Schelling, H. Singh, R. Marzec and S. L. Linas
Department of Medicine, University of Colorado Health Sciences Center, Denver 80262.

Angiotensin II (ANG II) stimulates proximal tubule sodium transport by decreasing adenylyl cyclase activity. The role of ANG II-dependent phospholipase C is less certain. To determine the contribution of phospholipase C and adenylyl cyclase to apical (AP) ANG II-dependent sodium transport, unidirectional (AP to basolateral) 22Na flux was measured in rat proximal tubule cells cultured on permeable supports. AP ANG II (100 nM)-dependent sodium flux was prevented by preincubation with concentrations of the phospholipase C inhibitor U-73122 (1 microM) that blocked ANG II-dependent inositol phosphate formation. AP ANG II-dependent sodium flux was also abolished by preincubation with the intracellular calcium mobilization inhibitor 3,4,5-trimethoxybenzoic acid 8-(diethylamino)octyl ester (TMB-8), further suggesting that ANG II-dependent sodium transport was mediated by inositol phosphates. Neither U-73122 nor TMB-8 prevented ANG II-dependent adenosine 3',5'-cyclic monophosphate (cAMP) decreases. Incubation with dibutyryl cAMP (10 microM) or forskolin (10 microM) prevented ANG II-dependent sodium flux as well as ANG II-dependent inositol phosphate formation. In conclusion, ANG II-dependent proximal tubule sodium transport in cultured cells was transduced by phospholipase C and adenylyl cyclase. The adenylyl cyclase effect on ANG II-dependent sodium transport was mediated by phospholipase C.

This article has been cited by other articles:

				J. L. Zhuo, X. C. Li, J. L. Garvin, L. G. Navar, and O. A. Carretero Intracellular ANG II induces cytosolic Ca2+ mobilization by stimulating intracellular AT1 receptors in proximal tubule cells Am J Physiol Renal Physiol, June 1, 2006; 290(6): F1382 - F1390. [Abstract] [Full Text] [PDF]

				J. P. Lea, S. G. Jin, B. R. Roberts, M. S. Shuler, M. B. Marrero, and J. A. Tumlin Angiotensin II Stimulates Calcineurin Activity in Proximal Tubule Epithelia through AT-1 Receptor-Mediated Tyrosine Phosphorylation of the PLC-{gamma}1 Isoform J. Am. Soc. Nephrol., July 1, 2002; 13(7): 1750 - 1756. [Abstract] [Full Text] [PDF]

				T. Thekkumkara and S. L. Linas Role of internalization in AT1A receptor function in proximal tubule epithelium Am J Physiol Renal Physiol, April 1, 2002; 282(4): F623 - F629. [Abstract] [Full Text] [PDF]

				E. Feraille and A. Doucet Sodium-Potassium-Adenosinetriphosphatase-Dependent Sodium Transport in the Kidney: Hormonal Control Physiol Rev, January 1, 2001; 81(1): 345 - 418. [Abstract] [Full Text] [PDF]

				T. J. Thekkumkara, R. Cookson, and S. L. Linas Angiotensin (AT1A) receptor-mediated increases in transcellular sodium transport in proximal tubule cells Am J Physiol Renal Physiol, May 1, 1998; 274(5): F897 - F905. [Abstract] [Full Text] [PDF]