Cardiac hypertrophy and telemetered blood pressure six weeks
following baroreceptor denervation in normotensive rats.
Vliet, Bruce N. Van, Lingqun Hu, Tom Scott, L. Chafe, and Jean-Pierre
Montani.
Faculty of Medicine, Memorial University of Newfoundland, St.
John's, Newfoundland, Canada, A1B 3V6 and Institute of Physiology,
University of Fribourg, Fribourg, Switzerland
APStracts 3:0252R, 1996.
We investigated cardiac morphometry 6 weeks following sino-aortic
baroreceptor denervation (SAD) in Long Evans rats. SAD (N=19) was
associated with an 11% increase in the weight of the left ventricle
(LV) plus septum (P<0.001), and a 39% increase in that of the
right ventricular (RV) free wall (P<0.001), relative to sham
operated rats (N=18). RV wall thickness was significantly increased
in SAD animals, but there was no difference in the LV wall thickness
and volumes of the RV and LV between groups. Constrictor responses to
methoxamine and dilation responses to acetylcholine were assessed in
an in vitro perfused mesenteric circulation preparation, but neither
response was affected by SAD. Baroreceptor denervation was associated
with marked and significant increases in the variability (2.8 fold)
and daily peak (39 mmHg) levels of telemetered mean arterial pressure
(MAP), and small (5%) but significant increases in the daily mean MAP
level. Our results are consistent with an effect of increased MAP
variability on ventricular weight, but cannot rule out possible
contributions from other mechanisms.
Received 29 December 1995; accepted in final form 19 June 1996.
APS Manuscript Number R827-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 4 July 96