Endothelium-mediated spontaneous response in aortic rings of deoxycorticosterone acetate-hypertensive rats.
- 1 March 1989
- journal article
- research article
- Published by Ovid Technologies (Wolters Kluwer Health) in Hypertension
- Vol. 13 (3), 256-261
- https://doi.org/10.1161/01.hyp.13.3.256
Abstract
Aortic rings isolated from normotensive Sprague-Dawley rts (CONT) exhibited spontaneous tone when the preparations were stretched. After administering deoxycorticosterone acetate (DOCA), the rats became hypertensive, and this spontaneous tone increased remarkably. The spontaneous tone was dependent on the extracellular calcium concentration. Incubation with the calcium entry blocker D-600 attenuated the spontaneous response to a greater degree in rings from DOCA rats than in rings from CONT rats. Nifedipine relaxed the already developed spontaneous tone. Removal of the endothelium greatly depressed spontaneous tone, but did not diminish the contraction caused by norepinephrine. On the basis of our findings, we conclude that 1) spontaneous tone depends on calcium unflux, presumably through specific stretch-operated channels, 2) these stretch-dependent channels are blocked by D-600 and nifedipine, 3) spontaneous tone is enhanced in DOCA hypertension, and 4) the endothelium appears to act as a receptor for stretch, mediating-at least in part.sbd.the spontaneous contractile response by releasing a constrictor agent.This publication has 20 references indexed in Scilit:
- A novel potent vasoconstrictor peptide produced by vascular endothelial cellsNature, 1988
- Single stretch-activated ion channels in vascular endothelial cells as mechanotransducers?Nature, 1987
- Increased Sensitivity to Nifedipine of Smooth Muscle from Hypertensive RatsJournal of Cardiovascular Pharmacology, 1986
- Role of endothelium in responses of vascular smooth muscle.Circulation Research, 1983
- Structural and functional changes in cerebral arteries from spontaneously hypertensive rats.Hypertension, 1983
- Selective action of diltiazem on cerebral vascular smooth muscle in the rabbit: Antagonism of extrinsic but not intrinsic maintained toneThe American Journal of Cardiology, 1982
- Comparison of Acute Effects of Nifedipine in Normotensive and Hypertensive ManJournal of Cardiovascular Pharmacology, 1980
- The Relationship Between Increased Myogenic Tone and Hyporesponsiveness in Vascular Smooth Muscle of Spontaneously Hypertensive RatsClinical and Experimental Hypertension, 1979
- Calcium leakage as a cause of the high resting tension in vascular smooth muscle from the spontaneously hypertensive rat.Proceedings of the National Academy of Sciences of the United States of America, 1978