THE EFFECT OF ADRENALINE OF THE VENTRICULAR MUSCLE OF TOAD

1. The effects of adrenaline in various concentration ( 1×10?6g/ml-1×10?4g/ml ) are studied on the still-standing and beating heart musles of japanese toads. 2. In low concentration of the drug or in early stage in high concentration, the action potential of standing heart muscle, especially the slow repolarization phase, is slightly prolonged. On the contrary, its duration of beating heart muscle is shortened by same procedure. 3. In later stage of large dosing of adrenaline, heart muscle ceases to beat in the systolic state and the resting potential shows a very low value ( 25mV-35mV ). 4.The relation between the ionic conductance of membrane and the action potential by the abministration of adrenaline was disdussed.