HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 289/6/H2434    most recent 00568.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (8) Citing Articles via Google Scholar Google Scholar Articles by Tang, E. H. C. Articles by Vanhoutte, P. M. Search for Related Content PubMed PubMed Citation Articles by Tang, E. H. C. Articles by Vanhoutte, P. M.

Acetylcholine and sodium nitroprusside cause long-term inhibition of EDCF-mediated contractions

¹Department of Pharmacology, Faculty of Medicine, University of Hong Kong, Hong Kong; ²Institut de Recherches Internationales Servier, Paris, France; and ³Department of Physiology, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong

Submitted 31 May 2005 ; accepted in final form 15 July 2005

Preliminary studies suggested that previous exposure to acetylcholine (ACh) exerts a delayed inhibition of subsequent contractions mediated by endothelium-derived contracting factor (EDCF). To confirm this long-term inhibitory effect of ACh and to determine whether nitric oxide (NO) mediates the phenomenon, we suspended rings of spontaneously hypertensive rat (SHR) aortas in organ chambers for the recording of isometric force. The rings were incubated in the absence or presence of N-nitro-L-arginine methyl ester (L-NAME; inhibitor of NO synthases) or 1H-[1,2,4]oxadiazolo[4,3-]quinoxalin-1-one (ODQ; inhibitor of soluble guanylyl cyclase) before exposure to increasing concentrations of ACh or sodium nitroprusside (SNP) during contractions to phenylephrine. Thereafter, EDCF-mediated contractions to ACh or the calcium ionophore A-23187 were elicited. If the rings were preexposed to ACh or SNP, the subsequent ACh-induced EDCF-mediated contractions were reduced compared with those obtained in rings of the same arteries not previously exposed to either agent. ODQ did not affect the inhibition caused by preexposure to ACh but significantly reduced that caused by preexposure to SNP. Previous exposure to SNP reduced, whereas previous exposure to ACh did not affect, endothelium-dependent contractions to A-23187. Previous exposure to either ACh or SNP did not affect the contractions to the thromboxane mimetic U-46619. Thus ACh and SNP exert delayed inhibition of EDCF-mediated contractions via distinct pathways. The effect of ACh is NO independent and upstream of the increase in calcium concentration that triggers the release of EDCF. The effect of SNP is downstream of the calcium rise and is mainly NO dependent.

endothelium-dependent contractions; endothelium-derived contracting factors; spontaneously hypertensive rats; nitric oxide

This article has been cited by other articles:

				C. K. Y. Chan, J. C. Mak, R. Y. K. Man, and P. M. Vanhoutte Rho Kinase Inhibitors Prevent Endothelium-Dependent Contractions in the Rat Aorta J. Pharmacol. Exp. Ther., May 1, 2009; 329(2): 820 - 826. [Abstract] [Full Text] [PDF]

				S. G. Denniss and J. W. E. Rush Impaired hemodynamics and endothelial vasomotor function via endoperoxide-mediated vasoconstriction in the carotid artery of spontaneously hypertensive rats Am J Physiol Heart Circ Physiol, April 1, 2009; 296(4): H1038 - H1047. [Abstract] [Full Text] [PDF]

				P. M. Vanhoutte and E. H. C. Tang Endothelium-dependent contractions: when a good guy turns bad! J. Physiol., November 15, 2008; 586(22): 5295 - 5304. [Abstract] [Full Text] [PDF]

				E. H. C. Tang and P. M. Vanhoutte Gap Junction Inhibitors Reduce Endothelium-Dependent Contractions in the Aorta of Spontaneously Hypertensive Rats J. Pharmacol. Exp. Ther., October 1, 2008; 327(1): 148 - 153. [Abstract] [Full Text] [PDF]

				M. S. K. Wong, R. Delansorne, R. Y. K. Man, and P. M. Vanhoutte Vitamin D derivatives acutely reduce endothelium-dependent contractions in the aorta of the spontaneously hypertensive rat Am J Physiol Heart Circ Physiol, July 1, 2008; 295(1): H289 - H296. [Abstract] [Full Text] [PDF]

				E. H.C. Tang, B. L. Jensen, O. Skott, G. P.H. Leung, M. Feletou, R. Y.K. Man, and P. M. Vanhoutte The role of prostaglandin E and thromboxane-prostanoid receptors in the response to prostaglandin E2 in the aorta of Wistar Kyoto rats and spontaneously hypertensive rats Cardiovasc Res, April 1, 2008; 78(1): 130 - 138. [Abstract] [Full Text] [PDF]

				E. H. C. Tang and P. M. Vanhoutte Gene expression changes of prostanoid synthases in endothelial cells and prostanoid receptors in vascular smooth muscle cells caused by aging and hypertension Physiol Genomics, February 19, 2008; 32(3): 409 - 418. [Abstract] [Full Text] [PDF]

				F. S. Michel, R. Y. K. Man, and P. M. Vanhoutte Increased spontaneous tone in renal arteries of spontaneously hypertensive rats Am J Physiol Heart Circ Physiol, September 1, 2007; 293(3): H1673 - H1681. [Abstract] [Full Text] [PDF]