Calcium, calcium-ATPase and cyclic AMP changes in Ehrlich ascites cells submitted to hyperthermia.

Increased radiocalcium influx, decreased Ca-ATPase activity and cAMP concentration were observed in Ehrlich carcinoma cells submitted to hyperthermia temperature (45 degrees C). The significant augmentation of mitochondrial calcium that is simultaneous to an inhibition of the calcium pump appears to indicate a heat-induced failure of the system of calcium-extrusion that may be responsible for cell inactivation and death through cell toxic death by calcium overloading. The decreased cAMP concentration appears to corroborate the influx of calcium.