The Influence of Trimetazidine on the Chemical Reaction between N-ethylmaleimide and L-cysteine

Abstract

The present experiment was performed to elucidate the problem whether N-ethylmaleimide (NEM) and trimetazidine react chemically in water solution or not as these drugs have shown the mutual antagonistic effects on isolated rat atrial tissue. Experiments were carried by means of the UV-spectrophotometer and the high speed liquid chromatography.
(1) The UV-absorbance by NEM at 302mμwas reduced by the coexistence of L-cysteine in the solution at soonafter their mixing, while was little influenced by the coexistence of trimetazidine when these drugs were mixed at the same molars. And, the absorbance by trimetazidine at 268mμ was little influenced by the coexistence of L-Cysteine in the solution.
(2) When NEM, L-cysteine and trimetazidine were coexisted in the solution, the appearance of NEM absorbance decrease induced by L-cysteine was delayed. In the experiment, in which rat erythrocytes were used as sulfhydryl preparation, the amount of NEM combined with erythrocytes might be reduced by the coexistence of trimetazidine.
(3) The reaction between NEM and trimetazidine in the solution was little proved by means of the high speed liquid chromatography, and that between NEW and propranolol was similar.
From these results, it was assumed that trimetazidine can influence the chemical reaction between NEM and SH radical, though the chemical reaction of trimetazidine with either NEM or L-cysteine is scarce.