Effect of electroacupuncture on calcium-activated chloride channel currents in interstitial cells of Cajal in rats with diabetic gastroparesis / 针灸推拿医学（英文版）

ABSTRACT

Objective: To investigate the mechanisms of electroacupuncture (EA) at Zusanli (ST 36), Liangmen (ST 21) and Sanyinjiao (SP 6) in intervening diabetic gastroparesis (DGP) based on calcium-activated chloride channel. Methods: Forty Sprague-Dawley rats were randomly divided into four groups, including a normal control group (group A), a model group (group B), an EA group (group C) and a metoclopramide group (group D), with 10 rats in each group. A single intraperitoneal injection of 2％ streptozotocin (STZ) combined with 8-week high-glucose high-fat diet was used to establish a DGP rat model. After intervention, gastrointestinal propulsive rate was observed; the expression level of transmembrane protein 16A (TMEM16A) was examined by immunohistochemistry; the Ca2+ concentration in interstitial cells of Cajal (ICCs) was detected by immunofluorescence; and whole-cell patch-clamp technique was applied to detect the current intensity of calcium-activated chloride channel (ICaCC) in ICCs in gastric antrum. Results: After modeling, the blood glucose levels in group B, group C and group D were significantly increased compared with group A (all P<0.01); after intervention, compared with group B, the blood glucose levels in group C and group D were significantly decreased (P<0.05, P<0.01); the intra-group comparison of blood glucose level between after modeling and after intervention found significant difference only in group C (P<0.01). The gastrointestinal propulsive rates in group B, group C and group D were significantly different from that in group A (P<0.01 or P<0.05); the gastrointestinal propulsive rates were markedly higher in group C and group D than in group B (P<0.01, P<0.01). The expressions of TMEM16A in group B and group C were decreased compared with group A (P<0.01, P<0.05); the expressions of TMEM16A in group C and group D were increased compared with group B (P<0.01, P<0.05). The fluorescence intensity of Ca2+ was significantly lower in group B than in group A (P<0.01); the fluorescence intensity of Ca2+ was significantly higher in group C and group D than in group B (P<0.01, P<0.05). ICaCC in ICCs in group B was significantly decreased compared with group A; ICaCC in group C and group D were increased compared with group B. Conclusion: EA at Zusanli (ST 36), Liangmen (ST 21) and Sanyinjiao (SP 6) can significantly improve gastrointestinal motility in DGP rats by up-regulating the ICaCC in ICCs.