A comparative study of the thermal dependence of contractility in saurian skeletal muscle

Abstract

1. 1. The effects of temperature on tension development in vitro were examined in the pubioischiotibialis muscle from five species of lizards.2. 2. Pronounced interspecific differences were evident in the optimal temperatures for isometric twitch tension and in the resistance to irreversible heat damage and heat rigor in the muscle.3. 3. A good correlation is evident between the thermal relations of the muscle and the extent of thermophily of the intact animal as judged by its preferred temperature and heat tolerance. Thus, adjustments at the tissue level appear to play a role in the thermal adaptations of lizards.