Journal of Applied Physiology, Vol 39, Issue 5 724-727, Copyright © 1975 by American Physiological Society
Regional vascular influences on tail-cuff measurements of drug-induced changes in systolic pressure
R. D. Bunag, N. Mueting and E. Riley
When drug effects are quantified using the tail-cuff method, changes in
systemic arterial pressure are extrapolated from those occurring in the
caudal artery. The validity of this extrapolation was tested in
anesthetized rats by recording drug-induced changes in phasic arterial
pressure simultaneously from catheters inserted into the lower abdominal
aorta, carotid, and caudal arteries. Pressor responses to norepinephrine or
angiotensin were of equal magnitude at all three sites, but phentolamine
reduced systolic pressure in the aorta or caudal artery more than that in
the carotid artery. Unlike previous discrepancies between carotid and
tail-cuff systolic pressures, aortic hypotension caused by injections of
phentolamine or pentolinium in awake normotensive or spontaneously
hypertensive rats was accurately predicted by the tail-cuff method. Because
drug-induced changes in diastolic pressure always varied much less than
those in systolic pressure, should indirect measurement of diastolic
pressure become technically feasible, it might be preferable for assessing
drug effects on blood pressure.
