Stroke, Vol 8, 589-594, Copyright © 1977 by American Heart Association
JD Spence, AB Pesout and KL Melmon
Increasing evidence suggests that higher blood velocity, by causing
turbulence and high shear rates at the endothelial surfaces of arteries,
may be important in the pathogenesis of atherosclerosis. In order to
measure the effects of antihypertensive agents on blood velocity, an
improved method has been developed for analysis of Doppler ultrasound
velocity recordings. The audio signal from a Doppler velocity meter is
subjected to spectral analysis; the sonagraph thus obtained is digitized
with the use of a magnetic table on-line with a calculator. Four monkeys
were maintained at a hypertensive baseline for six weeks by infusion of
angiotensin and isoproterenol. The effects on blood velocity of 72-hour
infusions of propranolol, clonidine, hydralazine, and methyldopa were
studied. In doses that reduced diastolic pressure by 13--28%, propranolol
decreased mean blood velocity (mv) by 17%, clonidine decreased mv by 14%,
while methyldopa increased mv 12%, and hydralazine increased mv by 52% (p
less than .00001). Antihypertensive drugs appear to have different effects
on blood velocity; these differences may influence choice of
antihypertensive drugs for the prevention of arterial disease.
ARTICLES
Effects of antihypertensive drugs on blood velocity in rhesus monkeys