| AIM:To observe the alterations of interstitial cells of Cajal (ICC) and connexin43 (Cx43) in gastric antrum tissue with the rat model of diabetic gastroparesis(DGP) and the intervention effect of insulin.METHODS:Eighty two Sprague-Dawley rats were random divided into three groups:control group,diabetic model group and insulin intervention group. Diabetes model was induced by a single dose intraperitoneal injection of streptozotocin (60mg/kg). All groups were breed with free access to water and food.Control group and diabetic model group were killed respectively at week 6,8 and 10. The rats of insulin intervention group who were kept six weeks were injected insulin glargine 8u/kg daily subcutaneously for four weeks and were killed at week 10. All groups were measured of gastric emptying rate by gavage administration of methylene blue and analyzed the expression of gastric antrum ICC and Cx43 by immunohistochemical method,observed the alterations of the ultrastructure of ICC and gap junction by transmission electron microscope.RESULTS:Diabetic model group resulted in hyperglycemia and weight loss,it was significant difference with control group (P<0.05). Blood glucose of insulin intervention group was between diabetic model group and control group,it was obviously different from them (P<0.05). Compared with the diabetic group,insulin intervention group was weight gain (P<0.05). The gastric emptying rate in diabetic model group was markedly decreased (PO.05). The gastroparesis models of diabetic rats were induced successfully. The gastric emptying rate was decreased with the prolonging of time (P<0.05) Immunohistochemical staining showed in rats gastric antrum that ICC were densely distributed between the circular and longitudinal muscle layers,Cx43 were expressed in the circular muscle layers. ICC and Cx43 in diabetic model group were lowly expressed (P＜0.05) and their expression were decreased with the time prolonging (P<0.05). Compared with the diabetic group,the number of ICC,Cx43 in the insulin intervention group were increased (P<0.05). TEM shown that ICC organelles degenerated,cytoplasm dissolved and the structure of gap junction loosed.Ultrastructure in insulirn intervention group was improved.CONCLUSION:1.The obvious pathological changes of ICC and Cx43,including the decrease and destruction of ICC and Cx43,might be the one of the pathophysiology of diabetic gastroparesis. The expression ICC and Cx43 were decreased with the time prolonging;2.Supplemental insulin could reverse lesions of ICC and Cx43,thus might improve the gastrointestinal disorders. |
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