Temperature dependence of the calcium paradox in the isolated working rat heart: Discrepancy between functional recovery and enzyme release

Abstract

We studied the effects of brief (2 min) acalcemic perfusion at various temperatures in isolated working rat hearts. Recovery of aortic flow, coronary flow and lactate dehydrogenase (LDH) release were measured upon reperfusion at 37°C. With acalcemic perfusion at 37°C, there was complete absence of functional recovery and impaired coronary flow. Acalcemic perfusion at 15°C and below resulted in complete recovery of function and coronary flow. Acalcemic perfusion between 20 and 30°C resulted in partial recovery of function and complete recovery of coronary flow. In contrast to this relationship of functional recovery to temperature, LDH release occurred only at 37°C. Thus, functional recovery does not correlate well with enzyme release over a range of acalcemic perfusion temperatures.