Paper Title
Morphological Changes of Gastric Smooth Muscle in Short-Termed Streptozotocin-Induced Diabetes

Abstract
In the diabetic patients, diminished gastric motility is a common symptom in the stomach, which leads to improper digestion and finally malnutrition. The gastric motility is a main function of smooth muscles, which are major component in the body and pylorus of stomach. Accordingly, the purpose of this study was to investigate morphological changes of gastric smooth muscles of pylorus, greater and lesser curvatures of body in the short-termed diabetic rats, compared with age-matched controls. Seven male adult Sprague-Dawley rats were divided into diabetic (n=4) and control (n=3) groups. The rats were intraperitoneally injected with streptozotocin in citrate buffer at a concentration of 60 mg/kg body weight in the diabetic groups, or only the same buffer was injected in the control groups. All of rats in both groups were sacrificed at 4 weeks after induction. Then, the stomachs were removed and processed in histological technique with hematoxylin and eosin staining and Masson’s Trichrome staining. The thickness of muscularisexterna and the number of smooth muscles were statistically analyzed by Mann-Whitney U test. In the diabetic group, the thicknesses of muscularisexterna were significantly thicker in all areas of stomach. Moreover, the numbers of smooth muscle cells significantly increased in all areas of diabetic stomach. Additionally, myofibroblasts were observed in the diabetic group. By using Masson’s Trichrome, intercellular fibrosis obviously rised in the diabetic group. Therefore, it was concluded that increased gastric smooth muscle cell number with intercellular collagen infiltration in the diabetes lead to abnormalities in muscular contraction and peristalsis, which might be causes of indigestion. Keywords - Diabetes Mellitus, Gastric Smooth Muscle, Streptozotocin