Electroacupuncture via Chronically Implanted Electrodes: Potential Treatment for Chemotherapy-Induced Delayed Emesis

We proposed a novel method of chronic electroacupuncture (EA) using implanted electrodes for the treatment of chronic chemotherapy-induced nausea and vomiting (CINV). We aimed to establish a rodent model of delayed emesis and explore EA effects on kaolin intake.

Saline-treated and cisplatin-treated rats underwent chronic placement of electrodes at bilateral PC6 and ST36 acupoints. Tested EA parameters included sham EA; EA at frequency of 10, 20, or 40 Hz; duration of one, three, or six hours; pulse width of 0.3, 0.6, or 1.2 msec; and amplitude of 0.4-2.0 mA. Kaolin intake was measured following each treatment.

1) Cisplatin increased kaolin intake (p ≤ 0.01 vs. saline). 2) In terms of reduction of kaolin intake vs. sham EA: a) EA at a frequency of 10 Hz was effective only when given for three hours (p = 0.0004). b) EA at a frequency of 20 Hz was effective when given for either one or three hours, with three hours being most effective (p = 0.007 and 0.005, respectively). c) EA at a frequency of 40 Hz was effective at six hours only (p = 0.04). 3) All different pulse widths significantly reduced kaolin intake, with 0.3 msec being most effective. 4) Using EA on both acupoints is superior to using EA on PC6 only (p = 0.005).

EA with parameters of 20 Hz, 0.3 msec for three hours on both PC6 and ST36 acupoints was found to be the best in reducing kaolin intake. Chronic EA with appropriate parameters is effective in reducing pica in a rodent model of CINV.