[Effect of acupuncture on contents of beta-endorphin in the plasma and hypothalamus in rats with stress-induced gastric mucosal injury].

Objective: To explore the mechanism of acupuncture in preventing and treating stress-induced gastric mucosal injury from the view of brain-gut axis.

Methods: Forty male Wister rats were randomly divided into normal control, model 1, treatment, model 2 and prevention groups (n=8). Gastric mucosa injury model was established by intragastric perfusion of dehydrated alcohol (1.0 mL/rat). Rats of the treatment group were treated with acupuncture after modeling, while those of the prevention group treated first, followed by modeling. The time of modeling in model 1 group and model 2 group was simultaneous with that of the treatment group and prevention group respectively. Acupuncture was applied to "Zusanli"(ST 36), "Zhongwan" (CV 12) and "Neiguan" (PC 6) for 20 min, once daily for 5 days. Before sampling the tissues, 10% charcoal suspension was intragastric perfused 1 h for analyzing the rate of gastrointestinal propulsion(distance from the upper end of the charcoal powder to the cardia/total length of the cardia to the anus x 100%). Gastric mucosal ulcer index was measured by using Guth's method. The contents of beta-endorphin(beta-EP)in plasma and hypothalamus were determined by enzyme-linked immunosorbent assay.

Results: Compared with the normal control group, the gastrointestinal propulsion rates were decreased considerably in the two model groups (P < 0.05), while the gastric mucosal ulcer indexes and the contents of beta-EP in both plasma and hypothalamus were increased significantly in the model groups (P < 0.05, P < 0.01). Compared with the corresponding model groups, the gastrointestinal propulsion rate was increased remarkably in the prevention group (P < 0.05), and the gastric mucosal ulcer indexes and the contents of plasma beta-EP level were decreased obviously in both treatment and prevention groups (P < 0.05, P < 0.01). The contents of hypothalamic beta-EP were increased further in the later two groups (P < 0.01).

Conclusion: Acupuncture of ST 36, CV 12 and PC 6 can promote the repair of gastric mucosal injury and improve gastrointestinal function, which may be related to its effects in reducing plasma beta-EP and upregulating hypothalamic beta-EP level. Acupuncture also has a better effect in preventing gastric mucosal injury.