AJP - Heart and Circulatory Physiology, Vol 250, Issue 5 761-H764, Copyright © 1986 by American Physiological Society

ARTICLES

Enhanced response of arterioles to oxygen during development of hypertension in SHR

J. H. Lombard, M. E. Hess and W. J. Stekiel

The goal of this study was to assess the possible role of O2-related local control mechanisms in contributing to an elevated skeletal muscle resistance during the development of hypertension in the spontaneously hypertensive rat (SHR). Diameters of first- (1A), second- (2A), third- (3A), and fourth-order (4A) arterioles were measured by television microscopy in the cremaster muscle of SHR in the early (4- to 6-wk-old) and rapidly developing (8- to 9-wk-old) stages of hypertension and in age-matched normotensive Wistar-Kyoto (WKY) controls. Active neurogenic tone was blocked by superfusing the tissue with 0.1 microgram/ml tetrodotoxin. When superfusion solution PO2 was elevated by changing the gas equilibration mixture from 0 to 5% O2, neurally blocked 3A and 4A of SHR exhibited a significantly greater constriction and a higher incidence of complete closure than those of their age-matched WKY controls. However, there were no significant differences in the constriction of larger arterioles (1A and 2A) in response to elevated superfusion solution PO2. The results suggest that O2-related local control mechanisms could contribute to constriction and closure of small arterioles and to an elevated skeletal muscle vascular resistance early in the development of hypertension in SHR.

This article has been cited by other articles:

				M. P. Kunert, I. Drenjancevic-Peric, M. R. Dwinell, J. H. Lombard, A. W. Cowley Jr., A. S. Greene, A. E. Kwitek, and H. J. Jacob Consomic strategies to localize genomic regions related to vascular reactivity in the Dahl salt-sensitive rat Physiol Genomics, September 14, 2006; 26(3): 218 - 225. [Abstract] [Full Text] [PDF]