Procaine enhancement of the rapid cooling contracture and inhibition of the decay of potentiated state in rabbit papillary muscle.

Abstract

We tested the possibility that inhibition of Ca2+ release from the sarcoplasmic reticulum decreases the transsarcolemmal Ca2+ efflux and results in an increased sarcoplasmic reticulum Ca2+ content. We used procaine to inhibit sarcoplasmic reticulum Ca2+ release in rabbit papillary muscles. Rapid cooling-induced contractures were used as an index of sarcoplasmic reticulum Ca2+ content. Decay of potentiated state was measured to study whether the transsarcolemmal Ca2+ efflux is decreased in the presence of procaine. Procaine (0.5, 1.0 mM) inhibited contractions elicited by electrical stimulation and enhanced the rapid cooling-induced contracture. The initial decay of potentiated state that occurs when the muscle was stimulated at a low frequency was slowed in the presence of procaine. These results suggest that procaine inhibition of Ca(2+)-induced release of sarcoplasmic reticulum Ca2+ decreases the transsarcolemmal Ca2+ efflux relative to the influx, resulting in an increased sarcoplasmic reticulum Ca2+ content.

• Authors: H Komai, D Redon, B F Rusy
• Journal: Journal of molecular and cellular cardiology (J Mol Cell Cardiol) Vol. 27 Issue 12 Pg. 2543-50 (Dec 1995) ISSN: 0022-2828 [Print] England
• PMID: 8825875 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Procaine
• Calcium

Topics

• Animals
• Calcium (metabolism)
• Heart Ventricles (drug effects)
• In Vitro Techniques
• Muscle Contraction
• Papillary Muscles (drug effects)
• Procaine (pharmacology)
• Rabbits