The effects of tetramethylpyrazine on the incidence of arrhythmias and the release of PGI2 and TXA2 in the ischemic rat heart

Pretreatment with tetramethylpyrazine (TMP, 12 mg/kg/day), a drug originally derived from the rhizomes of Ligusticum wallichii, significantly reduced the incidence of ischemia-induced ventricular tachycardia (VT) and fibrillation (VF) from 100 % and 50 % of control hearts to 41 % (p < 0.05) and 0 % (p < 0.05), respectively, in the ischemic rat heart. TMP also-diminished the incidence of reperfusion-induced VT and VF from 100 % and 100 % of control hearts to 33 % (p < 0.05) and 41 % (p < 0.05), respectively. Pretreatment with TMP produced a slight, but significant increase of 6-keto-PGF(1 alpha), and a decrease of TXB2 production during aerobic perfusion. Ischemia and reperfusion markedly increased the release of 6-keto-PGF(1 alpha) and TXB2. Pretreatment with TMP significantly enhanced the release of 6-keto-PGF(1 alpha) and diminished TXB2 outflow following left coronary artery occlusion and reperfusion.