WIRKUNG VON FENDILIN AUF HERZ UND GLATTE MUSKULATUR

The pharmacologic properties of fendiline N(1 phenylethyl[1]) 3,3 diphenylpropylamine hydrochloride, Sensit, were investigated in the isolated guinea pig heart and in isolated circular smooth muscle strips of bovine coronary arteries, pulmonary arteries and trachea. Fendiline dependently increased coronary flow by up to 200% but, in contrast to verapamil, did not inhibit contraction. Fendiline dependently relaxed coronary strips and, more powerfully, tracheal and pulmonary arterial strips. In cardiac muscle, fendiline was almost completely retained for a prolonged period of time. In the smooth muscle tissues under study, fendiline accumulated twenty fold above the concentration present in the organ bath. In paced hearts, fendiline noncompetitively inhibited the positive inotropic effect of isoprenaline in doses that did not significantly depress the amplitude of isotonic contractions. In the guinea pig heart, adenosine uptake became progressively inhibited when the coronary flow increased. This 'washout' effect was definitely counteracted by fendiline and by NaNO₂ but was augmented by papaverine, hexobendine and dipyridamol. The counteraction of the 'washout effect' by fendiline as well as by NaNO₂ is most likely due to the opening of additional (previously closed) capillaries.