Long-term tuina can inhibit the occurrence of gastroparesis by protecting gastrointestinal function in diabetic rats.

BACKGROUND: Diabetic gastroparesis (DGP) is a common complication in the later stage of diabetes mellitus (DM). The aim of this study was to investigate the protective effect of long-term tuina on gastrointestinal (GI) function and the occurrence of DGP in diabetic rats. METHODS: Twenty healthy male SD rats were randomly divided into four groups: NC, DM, DM + GT, and DM + TT. DM was induced with streptozotocin and a high-fat, high-sugar diet for 6 weeks. The DM + TT group received tuina therapy (20 min/session, 5 times/week) for 6 weeks. Weekly random blood glucose, gastric emptying rate, and small intestinal propulsion rate were measured. Hematoxylin and eosin (HE) staining assessed gastric antrum and ileum pathology. Ca(2+)-Mg(2+)-ATPase and CS activities, and neuronal nitric oxide synthase (nNOS), calmodulin (CaM), and myosin light chain kinase (MLCK) mRNA and protein expressions were evaluated by PCR and Western blot. 5-HT content was measured by ELISA. Piezo2 and 5-HT4R expressions were analyzed by immunofluorescence staining to observe tuina's protective effect on GI function in DM rats. RESULTS: Random blood glucose measurements showed normal levels in the NC group, while other groups remained above 16.7 mmol/L. The DM group exhibited reduced gastric emptying and small intestinal propulsion rates, along with gastric antrum and ileum damage. The DM + TT group showed significant improvements in gastric emptying and intestinal propulsion rates, and reduced tissue damage compared to the DM group. In the DM + TT group, mRNA and protein expressions of CaM and MLCK in antrum tissue, and nNOS, CaM, and MLCK in ileum tissue, were significantly increased. Activities of Ca(2+)-Mg(2+)-ATPase and CS enzymes in ileum tissue were also elevated, indicating enhanced GI function. Further analysis showed increased mRNA expressions of Piezo2 and 5-HT4R, and protein expressions of Piezo2, 5-HT, and 5-HT4R in the ileum tissues of the DM + TT group. Immunofluorescence intensity of Piezo2 and 5-HT in the ileum was also heightened. These results suggest that tuina's protective effect on GI function is related to the expression of Piezo2 ion channels. CONCLUSIONS: Long-term tuina protects the GI function of DM rats and inhibits the occurrence of DGP, which might be related to the Piezo2/5-HT pathway.