AJP - Heart and Circulatory Physiology, Vol 242, Issue 3 477-H484, Copyright © 1982 by American Physiological Society
Changes in arterial wall properties during development and maintenance of renal hypertension
R. H. Cox
Segments of carotid and tail arteries were used to determine the effects of
two-kidney Goldblatt hypertension on mechanical properties and chemical
contents. Arteries were obtained after 4 and 12 wk of hypertension.
Systolic pressures averaged 129 mmHg in control animals and 150 mmHg in
hypertensive ones. Pressure-diameter data were recorded under conditions of
active (145 mM K+) and passive (0 Ca2+ and 2 mM EGTA) smooth muscle. Small
increases in passive stiffness were found after 4 and 12 wk in the carotid
arteries of hypertensive animals, but no significant change occurred in the
tail arteries. Small but significant decreases in total connective tissue
content of these arteries were found after 12 wk of hypertension. Maximum
values of active stress response were significantly larger in carotid
arteries from hypertensive animals at both 4 and 12 wk of hypertension. No
significant differences were found for the tail arteries. The K+ content of
the carotid but not the tail artery was larger for the hypertensive
animals. When corrected for differences in relative cell content most of
the differences in active force development were eliminated. The
differences in passive mechanics can not be explained on the basis of the
changes in connective tissue content. The active smooth muscle responses
and content changes suggest that they are directly related to the moderate
elevation of arterial pressure.
