Proceedings of The Physiological Society

University of Central Lancashire (2002) J Physiol 543P, S236


Novel action of some organic calcium channel blockers on frog myocardium

S. Subramani, E. Tharion and C. Vijayanand

Department of Physiology, Christian Medical College, Vellore 632 002, India

  • "Figure 1. Effect of 10 µM diltiazem on relative post-rest contraction amplitude in strips of frog ventricle (mean ± S.D., n = 4). *P < 0.05, **P < 0.01, ***P < 0.001."

Gradual loss of sarcoplasmic reticular (SR) calcium during a rest period is responsible for the rest-induced decay of force of contraction in the mammalian myocardium (Reiter, 1988). The effect of two organic calcium channel blockers (OCCB), verapamil and diltiazem, on a similar 'rest-induced decay' (RID) in the frog myocardium suggests a new mechanism of action of these drugs.

Strips of frog ventricle from isolated hearts of pithed frogs (Rana hexadactyla) were mounted in a temperature-controlled bath (25

Where applicable, experiments conform with Society ethical requirements