The effect of stretch on contraction and the ca2+ transient in
ferret ventricular muscles during hypoxia and acidosis.
Hongo, K., White, E. & Orchard, C. H.
Department of Physiology, University of Leeds, Leeds LS2 9JT,
U.K.
APStracts 2:0168C, 1995.
The effect of stretch on cardiac muscle contraction and the Ca2+
transient was studied during hypoxia and acidosis in isolated ferret
ventricular muscles. In control conditions, a maintained stretch
produced an immediate increase in tension followed by a slow increase
in tension and the Ca2+ transient. A stretch between contractions
(diastolic stretch) caused only a slow increase in tension and the
Ca2+ transient, whereas a stretch during the period of contraction
(systolic stretch) produced an immediate increase in tension followed
by a small slow increase in tension and the Ca2+ transient. In
hypoxia, the immediate percentage increase in tension was the same as
in control. However, the slow increase was smaller during all three
types of stretch. In acidosis, the immediate percentage increase in
tension was larger than in control. The slow change was the same
during maintained stretch. However, the slow increase in tension was
smaller during diastolic stretch and larger during systolic stretch.
Thus the stretch dependent increase in contraction is inhibited
during hypoxia and modulated by acidosis.
Received 1 November 1994; accepted in final form 11 April 1995.
APS Manuscript Number C651-4.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 25 April 1995.