P6 Electroacupuncture Improved QTc Interval Prolongation by Upregulation of Connexin43 in Droperidol Treated Rats.

Aim. This study investigated the effect of P6 EA on droperidol-induced QTc interval prolongation and Cx43 expression in ventricular muscle of rats. Methods. Twenty-four rats were randomly divided into control group (C), droperidol group (D), or EA group (E). C group rats were injected with normal saline. D group rats were injected with droperidol 0.13 mg/kg. E group rats were pretreated with EA at left P6 acupoint for 30 min and then injected with droperidol (0.13 mg/kg). QTc intervals were recorded at lead II in ECG within 120 min. Cx43 expression was measured by RT-PCR and western blotting. Result. Droperidol significantly prolonged QTc intervals compared with controls at 5 min, 10 min, 15 min, and 30 min (P < 0.05). P6 EA could significantly abbreviate the prolongation of QTc interval compared with droperidol group at 5 min, 10 min, 15 min, and 30 min (P < 0.05). Cx43 mRNA and proteins were significantly increased by P6 EA compared with droperidol group at 120 min (P < 0.05). There were no significant differences in Cx43 mRNA and protein expression between droperidol and control group at 120 min (P > 0.05). Conclusion. P6 EA could improve QTc interval prolongation induced by droperidol, which may relate to upregulation of Cx43 mRNA and protein. Antiemetic dose of droperidol had minor effects on Cx43 mRNA and protein expression at 120 min.