ABSTRACT
OBJECTIVE: To explore the potential mechanism of acupuncture stimulation of "Taichong" (LR 3) and "Neiguan" (PC 6) in spontaneous hypertension rats (SHR) by investigating its effects on blood pressure and contents of aspartic acid(Asp) and glutamic acid (Glu) in the rostral ventrolateral medulla (RVLM) region. METHODS: A total of 75 SHR were randomized into model group, Taichong (LR 3) group, Neiguan (PC 6) group, LR 3+non-acupoint group and LR 3 + PC 6 group (n=15 rats in each group), and 15 Wistar rats of the same age were used as the normal control group. The filiform needles were inserted into the abovementioned acupoints and non-acupoint, twirled for a while and then retained for 30 min. The treatment was conducted once per day, 15 times in total. The rats' tail blood pressure was examined on day 1, 3, 7 and 15 after acupuncture treatment by using a non-invasive blood pressure monitor. At the end of experiment, the contents of Asp and Glu in the RVLM were detected by high-performance liquid chromatography with UV technique. RESULTS: On day 1, 3, 7 and 15 after the acupuncture treatment, the raised systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial blood pressure (MBP) of PC 6, LR 3, LR 3 + non-acupoint and LR 3 + PC 6 groups were all decreased significantly compared with the model group (P<0.05). On day 15, the effect of the LR 3 + PC 6 group was significantly superior to that of the LR 3, PC 6, and LR 3 + non-acupoint groups in reducing the levels of SBP, DBP, and MBP (P<0.05).Compared with the normal control group, the contents of Asp and Glu in RVLM were significantly higher in the model group (P<0.05). After acupuncture intervention, both Asp and Glu levels in the PC 6, LR 3, LR 3 + non-acupoint, and LR 3 + PC 6 groups were markedly lower in comparison with the model group (P<0.05), and those of the LR 3 + PC 6 group were notably lower than those in the LR 3 and PC 6 groups (P<0.05). CONCLUSIONS: Acupuncture stimulation of PC 6, LR 3, LR 3 + non-acupoint and LR 3 + PC 6 (in particular) is effective in lowering blood pressure in spontaneous hypertension rats, which may be associated with its effects in lowering Asp and Glu contents in RVLM.
