Right ventricular contractile protein function in rats with left
ventricular myocardial infarction.
Tombe, Pieter P. De, Thomas Wannenburg, Dongsheng Fan, William C.
Little.
Section on Cardiology, Bowman Gray School of Medicine, Wake Forest
University, Winston-Salem, North Carolina 27157-1045
APStracts 3:0108H, 1996.
We studied contractile function in cardiac trabeculae isolated from
the right ventricles (RV) of rats with experimental HF, induced by
left ventricular myocardial infarction (24 wk's post MI; n=6), and
from Sham operated rats (n=7). Sarcomere length (SL) was measured by
laser diffraction techniques and force (F) was measured by silicon
strain gauge. SL was kept constant at all times by computer feedback
control. HF was associated with marked left ventricular dilation and
pulmonary congestion. In intact, RV twitching trabeculae, HF was
associated with a depression of the F-SL relation at [Ca2+]o=1.5 mM
and a depression of the F-[Ca2+]o relation at SL=2.0[mu]m. HF was
also associated with a significant depression of the F-[Ca2+]i
relation at SL=2.0 [mu]m measured following chemical permeabilization
of these RV trabeculae (skinned fibers). Our results suggest that
reduced force development in this model of heart failure is due, in
part, to depressed function of the contractile filaments.
Received 25 May 1995; accepted in final form 11 November 1995.
APS Manuscript Number H485-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 27 March 96