Effects of temperature on anion distribution in perfused rat, guinea-pig and hamster ventricle

Ventricular tissue from rats, guinea-pigs and hamsters were found to be more anion permeable when perfused and superfused with Ringer's solution at 22 degrees C rather than 36 degrees C. When the perfusate temperature was 36 degrees C the anion permeability of the in vitro rat and guinea-pig ventricle approximated that found in situ. Further, the anion permeability of the rat and guinea-pig heart was found not to be influenced by the absence of plasma proteins in the perfusate.