The effects of tetramethylpyrazine on the incidence of arrhythmias and therelease of PGI(2) and TXA(2) in the ischemic rat heart

Pretreatment with tetramethylpyrazine (TMP, 12 mg/kg/day), a drug originall y derived from the rhizomes of Ligusticum wallichii, significantly reduced the incidence of ischemia-induced ventricular tachycardia (VT) and fibrilla tion (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 th e incidence of reperfusion-induced VT and VF from 100 % and 100 % of contro l 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.