Effect of electroacupuncture of "Chize" (LU 5) and "Shangjuxu" (ST 37) on mesenteric microcirculation and vasoactive intestinal peptide levels in the lung, colon and hypothalamus in rats with chronic obstructive pulmonary diseases]

To observe the influence of electroacupuncture (EA) of "Chize" (LU 5, He-sea acupoint) and "Shangjuxu" (ST 37, lower He-sea acupoint) on mesenteric microcirculation, vasoactive intestinal peptide (VIP) levels in the lung, colon and hypothalamus tissues in rats with chronic obstructive pulmonary disease (COPD), so as to investigate its mechanism underlying improvement of lung derived intestinal disorders in clinical practice.Thirty-two male Wistar rats were randomly divided into normal control, model, EA-Chize (LU 5, EA-LU 5) and EA-Shangjuxu (ST 37, EA-ST 37) groups, with 8 rats being in each group. COPD model was established by intratracheal infusion of Lipopolysaccharide (LPS, 1 mg/mL, 0.2 mL/rat) and forced inhaling smoke, once daily for 28 days. EA was applied to bilateral LU 5 and ST 37 for 20 min, once every other day for 12 sessions. The state of mesenteric microcirculation was observed under microscope and divided into grade 0 (stagnation of blood flow), I (slow flowing and silt-like state), II (faster flowing with slight or obvious grainy feeling) and III (fast flowing without grainy feeling). The contents of VIP in the lung, colon and hypothalamus were detected using radioimmunoassay (RIA).Following modeling, the microvascular calibers were increased slightly in the model, EA-LU 5 and EA-ST 37 groups. Compared with the normal group, the blood flow velocity was increased significantly in model group (P < 0.05). In comparison with the model group, the blood flow velocity was reduced significantly in EA-LU 5 and EA-ST 37 groups (P < 0.01). There were no significant differences between EA-LU 5 and EA-ST 37 groups in blood flow velocity, among the four groups in VIP contents of the lung tissue (P > 0.05). The content of VIP in the colon was markedly higher in the model group than in the normal group, and that in the hypothalamus was obviously lower in the EA-LU 5 group than in the model group (all P < 0.05).EA stimulation of "Chize" (LU 5) can notably reduce hypothalamic VIP content and slow down blood flow velocity of the mesenteric microvessels in COPD rats.