[Anti-calcium effects of 4-hydroxypropiophenone derivatives--potential beta-adrenoreceptor blockers]

The present paper carries out the pharmacological evaluation of 4-(2-hydroxy-3-isopropylaminopropoxy)-3-(alkoxymethyl) propiophenones with an ethoxy, propoxy and butoxy-group, whose structures are typical of the blockers of beta-adrenergic receptors. In the above-mentioned compounds the anticalcium effect on the frequency and the amplitude and the negative chronotropic and the negative inotropic effects were evaluated by means of the method of spontaneously pulsing guinea-pig atria within a concentration range of 4-16 microgram.cm-3. The obtained results confirmed a significant anticalcium effect on the heart rate in the compounds with a propoxy and a butoxy group, and in the standard verapamil. In all three compounds as well as in the standard verapamil, no anticalcium effect on the amplitude was found. The results of this membrane efficacy are in agreement with the preceding evaluation of the antidysrhythmic and anti-isoprenaline activity with the most marked effect in the compound with a propoxy group. On the basis of these results it is possible to conclude that in these derivatives of 4-hydroxypropiophenone also the anticalcium effect can participate, besides the beta-adrenolytic and the membranostabilizing effects, in the antidysrhythmic activity.