Effects of captopril on prostaglandin-thromboxane relation during myocardial ischemia induced by ventricular pacing EFECTOS DE CAPTOPRIL EN LA RELACION PROSTAGLANDINA/TROMBOXANO DURANTE LA ISQUEMIA INDUCIDA POR ESTIMULACION VENTRICULAR

Abstract

To evaluate the possible role of captopril during pacing induced ischaemia we studied 7 patients with stable coronary artery disease. Coronary sinus blood levels of thromboxane-B2 (TXB2), prostaglandin-F1 alpha (PGI2), PGI2/TXB2 ratio and plasma renin activity were measured. An important increase in blood levels of PGI2 and TXB2 and reduction of PGI2/TXB2 ratio was observed during pacing induced ischaemia [1.16 ± 0.39 to 0.43 ± 0.09 (p < 0.01)]. After 25-50 mg of oral captopril PGI2/TXB2 during pacing increased from 0.68 ± 0.22 to 0.85 ± 0.14 (p = NS and p < 0.05 vs 0.43 ± 0.09). No changes in plasma renin activity levels were observed. Captopril reduced the excretion of prostanoids during pacing induced ischaemia without a significant change in PGI2/TXB2 ratio, a fact that could contribute to cardioprotection given by captopril during the acute coronary events.