Slow inward and outward currents of rat ventricular fibers under anoxia

Voltage and current clamp experiments were performed on rat ventricular strips under anoxia. 1. Under the influence of anoxia the membrane depolarized by 5 to 10 mV and the action potential amplitude decreased by 15 mV. The plateau disappeared and the duration of the action potential was shortened. 2. The slow inward current was reduced by 50 to 80% and its reversal potential became more negative by about 31 mV. The conductance of the slow inward channel decreased by 26%. 3. The net outward current was slightly depressed.