Abstract
The effects of xylopinine on the adrenergic mechanism of the isolated guinea-pig's atria were studied. Xylopinine in concentrations above 10-8 depressed the rate of the atrial beat without affecting the concentration. During the early phase of the atrial depression by xylopinine the chronotropic effects of adrenaline and isopropylnoradrenaline were depressed, while the same effects were potentiated during the late phase of the depression.
