OBJECTIVETo explore the effects of principal-subordinate acupoints combination on improving myocardial ischemia, and the gene regulatory pathways for the protection of myocardial ischemia.

METHODSAccording to the random number table method, 70 SPF Wistar male rats were divided into a normal group, a model group, a LY294002 group, an insulin-like growth factors-1(IGF-1) group, a Neiguan group, an acupoint combination group and an acupoint combination + LY294002 group, 10 rats in each one. Rats in the normal group were injected with 0.9% NaCl solution, while rats in the remaining groups were treated with abdominal subcutaneous injection of isoroterenol hydrochloride to establish the rat model of myocardial ischemia. Rats in the LY294002 group and IGF-1 group were treated with injection of LY294002 solution and IGF-1 solution for 14 days. Rats in the Neiguan group were treated with electroacupuncture (EA) at "Neiguan" (PC 6) by using Han-200 EA apparatus for 10 min per treatment. Rats in the acupoint combination group were treated with EA at "Neiguan" (PC 6), "Zusanli" (ST 36) and "Guanyuan" (CV 4) by using Han-200 EA apparatus for 10 min per treatment. Rats in the acupoint combination + LY294002 group were treated with LY294002 solution for 14 days, and EA at "Neiguan" (PC 6), "Zusanli" (ST 36) and "Guanyuan" (CV 4) was given before model establishment, once a day for 21 days. EA pretreatment was given before model establishment in all acupuncture groups. The heart rate (HR) and ST segment voltage were detected before and after treatment; the myocardial pathological morphology was observed by HE staining; the expressions of P13K mRNA and Akt mRNA were tested.

RESULTSAfter modeling, HR and ST segment voltage in all intervention groups were higher than those in the normal group (all P < 0.01); after the intervention, the HR and the ST segment voltage in the acupoint combination group, IGF-1 group and IGF-1 group were improved (P < 0.01, P < 0.05), which was more significant in the acupoint combination group and Neiguan group (all P < 0.01). As for the myocardial pathological morphology, obvious myocardial ischemia was observed in the model group, and that in the LY294002 group was the most serious, and that in the acupoint combination+ LY294002 group was moderate. After intervention, the myocardial pathological damage in the IGF-1 group, Neiguan group and acupoint combination group was significant improved, which was more significant in the IGF-1 group and acupoint combination group. As for the expression of PI3K mRNA and Akt mRNA, compared with normal group, the expression of PI3K mRNA was increased in the remaining groups after modeling (P < 0.01, P < 0.05), which was more significant in the IGF-1 group and acupoint combination group (all P < 0. 01). The expression of Akt mRNA in the LY294002 group and acupoint combination + LY294002 group was reduced (P < 0. 01, P < 0.05), while that in the remaining groups was increased (P < 0.01, P < 0.05), which was more significant in the IGF-1 group and acupoint combination group (all P < 0.01).

CONCLUSIONThe principal-subordinate acupoints combination could improve heart rate and ST segment voltage in rats with chronic myocardial ischemia, reduce myocardial pathological damage, which is superior to single selection of "Neiguan" (PC 6). The PI3K/Akt signaling pathway may be involved in the regulation mechanism of principal-subordinate acupoints combination for the protection of chronic myocardial ischemia.