The control of renal and mesenteric conductance during hemorrhage
in conscious hypertensive rabbits.
Weichert, Gabriele, and Carol-Ann Courneya.
Department of Physiology, University of British Columbia,
Vancouver, B.C. V6T 1Z3, Canada
APStracts 3:0149H, 1996.
Control of renal and mesenteric conductance during hemorrhage was
examined in conscious renal wrap hypertensive rabbits. Hemorrhage was
performed under control conditions and during blockade of 1)
vasopressin (AVP) and angiotensin II (ANG II), 2) the autonomic
nervous system (ANS), and 3) the ANS, AVP and ANG II. We hypothesized
that hypertensive rabbits would have impaired hormonal and autonomic
control of renal and mesenteric conductance. When the ANS was intact,
hypertensive rabbits had an impaired ability to control blood
pressure, but no impairment in renal and mesenteric vasoconstriction
during hemorrhage. When the ANS was blocked, AVP/ANG II mediated
control of blood pressure was not observed during hemorrhage, but was
observed during a two minute pause after hemorrhage was terminated.
During this pause (ANS blocked), the hypertensive rabbits did not
exhibit an impaired vasoconstriction of the renal or mesenteric beds.
We conclude that, although the hypertensive rabbits had an impaired
ability to control blood pressure during hemorrhage, this was not
associated with an impaired ANS or AVP/ANG II mediated control of
renal or mesenteric vascular conductance.
Received 16 August 1995; accepted in final form 26 March 1996.
APS Manuscript Number H773-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 16 April 96