[Effects of ligustrazine on myocardium and coronary artery].

OBJECTIVE

To study the effects of ligustrazine on mechanical electricity in guinea pig ventricular papillary muscles and on contraction of pig coronary artery.

METHOD

Standard glass microelectrode technology; electrophysiological method; and blood vessel perfusion were used.

RESULT

1. ligustrazine(3-100 mumol/L) suppressed the action potential duration (APD) and the force of contraction (FC) of the fast action potentials (FAP), as well as the action potential amplitude (APA), APD, FC and the maximal upstroke velocity(Vmax) of the slow action potentials (SAP). 2. ligustrazine (3.0 mmol/L) induced SAP and contraction, but failed in beta-adrenoreceptor blocked muscles. Elevation of[Ca2+]o increased the action potential amplitude (APA). 3. ligustrazine(10(-5)-5 x 10(-3) mol/L) decreased the contractile response to high KCl in pig coronary artery.

CONCLUSION

Ligustrazine might affect the inward current of myocardial cells through beta-adrenoreceptor, and the diastolizing effect of ligustrazine on coronary artery might have nothing to do with the exciting beta-adrenoreceptor.