Temperature dependence of Na+-H+ exchange, Na+-HCO3- co-transport, intracellular buffering and intracellular pH in guinea-pig ventricular myocytes.

Almost all aspects of cardiac function are sensitive to modest changes of temperature. We have examined the thermal sensitivity of intracellular pH regulation in the heart. To do this we determined the temperature sensitivity of pHi, intracellular buffering capacity, and the activity of sarcolemmal acid-extrusion proteins, Na+-H+ exchange (NHE) and Na+-HCO3- co-transport (NBC) in guinea-pig isolated ventricular myocytes.