This Article Full Text Full Text (PDF) 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 PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Martin, P. Articles by Krum, H. Search for Related Content PubMed PubMed Citation Articles by Martin, P. Articles by Krum, H. Related Collections Cardiovascular Pharmacology Clinical Studies Endothelium/vascular type/nitric oxide

(Hypertension. 2002;39:821.)
© 2002 American Heart Association, Inc.

Scientific Contributions

Effect of Endothelin Blockade on Basal and Stimulated Forearm Blood Flow in Patients With Essential Hypertension

Paul Martin; Daniel Ninio; Henry Krum

From the Clinical Pharmacology Unit, Departments of Medicine and Epidemiology & Preventive Medicine, Monash University, Alfred Hospital, Melbourne, Australia.

Correspondence to A/Prof Henry Krum, PhD, FRACP, Clinical Pharmacology Unit, Department of Epidemiology and Preventive Medicine/Department of Medicine, Monash University/Alfred Hospital, Prahran Victoria 3181 Australia. E-mail henry.krum{at}med.monash.edu.au

Endothelin receptor antagonism lowers blood pressure in patients with essential hypertension, but the contribution of the endothelin system to increased vascular tone in these patients remains controversial. We used strain-gauge venous plethysmography to measure changes in basal and metabolically stimulated (peak reactive hyperemia [PRH]) forearm blood flow (FBF) induced by continuous intrabrachial infusion of SB 209670, a dual endothelin type A/endothelin type B receptor antagonist (ETRA) in 11 patients with hypertension and 12 healthy age-matched control subjects. In both groups, ETRA caused significant vasodilation (increase in FBF compared with baseline over the last 30 minutes of ETRA infusion: 75±12% in control subjects, 40±13% in hypertension patients; P<0.01 for both groups). By repeated-measures ANOVA, there was no greater increase in FBF after ETRA in hypertension patients compared with control subjects. In addition, FBF responses to PRH, expressed as percent change from baseline (prePRH), were similar in both groups (control subjects: preETRA, 1381±222%; during ETRA, 921±178%; and hypertension patients: preETRA, 1232±221%: during ETRA, 865±285%). We conclude that basal and stimulated vasodilation induced by short-term ETRA infusion in the forearm vasculature of hypertension patients is not increased compared with that of control subjects. An enhanced contribution of the endothelin system to vascular tone in hypertension patients could not be demonstrated using this experimental approach.

Key Words: endothelin • hypertension, essential • plethysmography • blood flow • SB 209670

This article has been cited by other articles:

				N. Dhaun, J. Goddard, D. E. Kohan, D. M. Pollock, E. L. Schiffrin, and D. J. Webb Role of Endothelin-1 in Clinical Hypertension: 20 Years On Hypertension, September 1, 2008; 52(3): 452 - 459. [Full Text] [PDF]

				N. Dhaun, J. Goddard, and DavidJ. Webb The Endothelin System and Its Antagonism in Chronic Kidney Disease J. Am. Soc. Nephrol., April 1, 2006; 17(4): 943 - 955. [Abstract] [Full Text] [PDF]

				L. M. Boak, A. M. Dart, S. J. Duffy, and J. P. F. Chin-Dusting Responses to neither exogenous nor endogenous endothelin-1 are altered in patients with hypercholesterolemia J. Lipid Res., December 1, 2005; 46(12): 2667 - 2672. [Abstract] [Full Text] [PDF]

				J. Goddard, D. J. Webb, P. Martin, and H. Krum Endothelin Antagonists and Hypertension: A Question of Dose? * Response Hypertension, September 1, 2002; e2(3): . [Full Text] [PDF]

				C. M. McEniery, I. B. Wilkinson, D. G. Jenkins, and D. J. Webb Endogenous Endothelin-1 Limits Exercise-Induced Vasodilation in Hypertensive Humans Hypertension, August 1, 2002; 40(2): 202 - 206. [Abstract] [Full Text] [PDF]