Abstract
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 lowering the oxygen consumption of the heart (2), but other mechanisms of its action yet awaited clarification.
Since trimetazidine exerts no appreciable effect on normal atria, the present experiments on the actions of this drug had to be carried out in atria under the influence of nicotine, 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 trimetazidine 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 trimetazidine molecule possesses trimethoxybenzene and piperazine in its own chemical structure (Fig. 1), these two substances also were individually tested in reference to atrial actions of trimetazidine.
