Effect of electroacupuncture on electrogastrogram and gastric antrum ghrelin in rats with diabetic gastroparesis

Objective To observe the effect of electroacupuncture (EA) on the electrogastrogram and gastric antrum ghrelin in rats with diabetic gastroparesis (DGP). Methods Fifty Sprague-Dawley (SD) rats were randomly divided into group A, group B, group C, group D and group E, 10 rats in each group. Group A was the blank control group without intervention. Group B, Group C, Group D and Group E were treated with single dose intraperitoneal injection of 2% streptozotocin (STZ), combined with 8-week high glucose and high fat diet to establish DGP rat models. Group B was the model group without treatment. Group C was the EA at acupoint group, was treated with EA at Zusanli (ST 36), Liangmen (ST 21) and Sanyinjiao (SP 6). Group D was the EA at non-acupoint group, was treated by EA at the control points of Zusanli (ST 36), Liangmen (ST 21) and Sanyinjiao (SP 6). Rats in the metoclopramide control group received 1.7% metoclopramide solution [10 mL/(kg·bw)] by gavage. Rat’s blood glucose level was measured by blood glucose meter; gastric emptying rate was detected using phenol red as a marker; the electrogastrogram was detected by BL-420F biological function system; the protein level of ghrelin was detected by enzyme-linked immunosorbent assay (ELISA); the expression of ghrelin mRNA was detected by real-time polymerase chain reaction (RT-PCR). Results Compared with group A, the blood glucose of group B, C, D and E were significantly increased before and after the treatment (all P <0.01); after treatment, the gastric emptying rate of group B was significantly decreased ( P <0.01), the migration rates of small intestine in group B, C, D and E were significantly lower (all P <0.01), and the protein content of ghrelin in group C was significantly decreased ( P <0.01); the expressions of ghrelin mRNA were significantly increased in group B, C, D and E (all P <0.01), the mean amplitudes of electrogastrogram in group B and D were significantly decreased (both P <0.01). After treatment, compared with group B, the blood glucose of group C was significantly decreased ( P <0.05), the gastric emptying rate and small intestine migration rate were significantly increased in group C and E ( P <0.05, P <0.01), the small intestinal migration rate was significantly increased in group D ( P <0.05), the expression of ghrelin in protein and mRNA in group C was significantly lower ( P <0.01), the expression of ghrelin mRNA in group E was significantly lower ( P <0.05), and the mean amplitude of electrogastrogram in group C was significantly increased ( P <0.05). After treatment, compared with group D, the protein and mRNA expressions of ghrelin in group C were significantly decreased ( P <0.01). After treatment, compared with group E, the protein expression of ghrelin in group C was significantly decreased ( P <0.01). Conclusion EA at Zusanli (ST 36), Liangmen (ST 21) and Sanyinjiao (SP 6) could regulate the blood glucose level of DGP model rats, enhance electrogastrogram activity, promote gastric emptying, and regulate ghrelin expression in protein and mRNA.