The actions of trimetazidine on isolated guinea-pig atria.

In 1969, the Servier Laboratoires introduced trimetazidine, 1-(2, 3, 4-trimethoxybenzyl) piperazine dihydrochloride (Vastarel®) as a medicament for angina pectoris (1). This drug is assumed to reveal its remarkable action through decreasing cardiac work and lower ing the oxygen consumption of the heart (2), but other mechanisms of its action yet await ed clarification. Since trimetazidine exerts no appreciable effect on normal atria, the present experi ments on the actions of this drug had to be carried out in atria under the influence of nico tine, potassium free medium, or electrical stimulation. The isolated guinea-pig atria were chosen as an experimental material, because of its high sensitivity to various drugs. The decreasing effect of trimetazidine on the toxicity of strophanthin-G in guinea-pig atria has already been reported in our previous paper (3), in which it was suggested that tri metazidine might exhibit its action through lessening the out-flow of the intracellular potassium in atria. The anti-nicotinic action of this drug has also been reported in one of our previous papers (4). Our previous experimental results led us to the present consideration of the relation between the chemical structure of the drug and its pharmacological actions. As the tri metazidine molecule possesses trimethoxybenzene and piperazine in its own chemical struc ture (Fig. 1), these two substances also were individually tested in reference to atrial ac tions of trimetazidine.