The Effect of Low Temperature on the Isolated Hearts of Citellus leucurus and C. mohavensis

Abstract

The perfused, isolated hearts of two desert-living ground squirrels, Citellus mohavensis and C. leucurus, were exposed to temperatures between 25° C and 0° C. Although mohavensis hibernates and aestivates and leucurus does neither, the temperature-rate curves were very similar and typical of hibernators in general. Leucurus is highly adapted to a diurnal existence in hot arid regions and has a high critical and lethal temperature, yet its heart has not changed its ability to tolerate low temperatures.