Endocrinology, Vol 128, 231-241, Copyright © 1991 by Endocrine Society

ARTICLES

Angiotensin-II-induced changes in diacylglycerol levels and their potential role in modulating the steroidogenic response

WB Bollag, PQ Barrett, CM Isales and H Rasmussen
Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510.

Angiotensin-II (Ang II) not only increases aldosterone secretion from bovine adrenal glomerulosa (AG) cells, but also primes these cells to respond to a subsequent challenge with the calcium channel agonist Bay K 8644. In cultured AG cells we investigated the hypothesis that this priming effect was the result of a persistent elevation in diacylglycerol (DAG) content. Ang II elicited an increase in DAG content, which was maintained for up to 75 min after the removal of Ang II, an effect which could underlie the ability of Ang II to prime the cells to respond to Bay K 8644. We then investigated the possibility that the DAG found in bovine AG cells consists of multiple species and the potential relationship of the species to the persistent elevation. We found that [3H]arachidonate and [14C]myristate were differentially incorporated into phospholipids, with approximately 80-85% of the latter radiolabel contained in phosphatidylcholine. Ang II elicited increases in the levels of both arachidonate- and myristate-containing DAG. The subsequent addition of an Ang II antagonist resulted in a rapid decrease in [3H]arachidonate-labeled DAG levels, but a much slower decline in myristate-containing DAG. These results suggest that the species of DAG generated in response to hormonal stimulation may be important in determining the speed with which this signal is terminated. Ang II also stimulated the release of water-soluble [3H]choline metabolites, in particular choline and phosphorylcholine, from prelabeled cells. These results indicate that 1) various DAG species exhibit different turnover rates; and 2) perhaps as a result of this disparity, the increase in DAG induced by an agonist may persist for a considerable period of time after the removal of the agonist or the inhibition of its action.

This article has been cited by other articles:

				W. B. Bollag, P. Kent, S. White, M. Malinova, C. M. Isales, and R. A. Calle Characterization and Phospholipase D Mediation of the Angiotensin II Priming Response in Adrenal Glomerulosa Cells Endocrinology, February 1, 2007; 148(2): 585 - 593. [Abstract] [Full Text] [PDF]

				J.-G. LeHoux and A. Lefebvre Novel protein kinase C-epsilon inhibits human CYP11B2 gene expression through ERK1/2 signalling pathway and JunB J. Mol. Endocrinol., February 1, 2006; 36(1): 51 - 64. [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]

				R. D. Griner, F. Qin, E. Jung, C. K. Sue-Ling, K. B. Crawford, R. Mann-Blakeney, R. J. Bollag, and W. B. Bollag 1,25-Dihydroxyvitamin D3 Induces Phospholipase D-1 Expression in Primary Mouse Epidermal Keratinocytes J. Biol. Chem., February 19, 1999; 274(8): 4663 - 4670. [Abstract] [Full Text] [PDF]