Attenuation of Endothelium-Dependent Relaxation in Mesenteric Artery during Noise-Induced Hypertension.
The present study was designed to determine whether there is a causal relationship between noise-induced hypertension and changes of endothelial function. Rats were exposed to noise stress (100 dB, 1 kHz, 4 h/day, 6 days/week) for 1-4 weeks. The systolic blood pressure was significantly increased after rats were exposed to noise stress for 3 weeks. The relaxant responses of isolated mesenteric arterial rings to endothelium-dependent vasodilators (A23187 and acetylcholine) in noise-treated rats were significantly less than those in control rats. This difference in response to acetylcholine still existed in the presence of methylene blue or N(omega)-nitro-L-arginine. On the other hand, the responses to the endothelium-dependent vasodilator nitroglycerin were not affected in rats exposed to noise stress. The attenuation to endothelium-dependent vasodilators during noise stress may result in increasing peripheral vascular resistance and thus elevate blood pressure. This indicates that noise-induced hypertension may be partly due to the alterations of endothelial activity. Copyright 1994 S. Karger AG, Basel
Wu
C.C.
CC
Department of Pharmacology, National Defense Medical Center, Taipei, Taiwan, ROC.
Chen
S.J.
SJ
Yen
M.H.
MH