[Effects of electroacupuncture on inflammatory response and intestinal mucosal barrier in obese rats with insulin
Huan Wu1, Feng-Xia Liang1, Bang-Guo Chen1
1College of Acupuncture-Moxibustion and Orthopedics, Hubei University of CM, Wuhan 430065, China.
Objective:
To observe the effects of electroacupuncture (EA) on inflammatory response and intestinal mucosal barrier in obese rats with insulin resistance, and to explore the mechanism of EA on improving insulin resistance in rats.
Methods:
Among 45 Wistar male rats, 15 rats were randomly selected and fed with common diet. After eight weeks, 10 rats were randomly selected and divided into the normal group. The remaining 30 rats were fed with high-fat diet for 8 weeks to establish obesity model of rat, among 28 rats with successful model of obesity, 20 rats were randomly selected and divided into the model group and EA group, 10 rats in each one. At the same time, 3 rats in the model group and the EA group were randomly selected for hyperinsulinemia-euglycemic clamp operation to determine whether the insulin resistance model was successful. After model establishment, the rats in the EA group were intervented with EA at "Zhongwan" (CV 12), "Guanyuan" (CV 4), "Zusanli" (ST 36) and "Fenglong" (ST 40) with continuous wave, frequency of 2 Hz and intensity of 1 mA; "Zusanli" (ST 36) and "Fenglong" (ST 40) were used alternately on both sides; the needles were sustained for 10 min; EA was given once every other day, three times a week for a total of 8 weeks. During the intervention, the rats in the normal group and the model group were fixed but not intervented. The body mass and postprandial blood sugar were measured in each group before and after 8-week intervention. After 6-week intervention, 3 rats in each group were clamped to detect systemic insulin sensitivity. Before the rats were killed, blood was taken from the apex of the heart to detect the serum insulin content. After the rats were killed, the mRNA levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in liver and adipose tissue and occlidin and ZO-1 in colon tissue were detected by Real time-PCR; the protein expression levels of occludin and ZO-1 in colon tissue were detected by Western blot method.
Results:
Compared with the normal group, the body mass, postprandial blood sugar and serum insulin content in the model group were increased significantly, the glucose infusion rate (GIR) was decreased significantly (all P<0.01), the mRNA expressions of TNF- and IL-6 in liver and adipose tissue were increased (P<0.05, P<0.01), the mRNA and protein expressions of ZO-1 in colon tissue were decreased significantly (both P<0.01), and the mRNA expression of occludin was significantly decreased (P<0.01). Compared with the model group, the body mass, postprandial blood sugar, serum insulin content, mRNA expressions of TNF-a and IL-6 in liver and adipose tissue were significantly decreased (P<0.01, P<0.05), GIR was significantly increased (P<0.01), and the mRNA and protein expressions of ZO-1 in colon tissue were increased (P<0.01, P<0.05).
Conclusion:
EA could decrease blood sugar and increase insulin sensitivity. Its mechanism may be related to inhibiting the expression of inflammatory factors and improving intestinal mucosal barrier.
