The Changes And Significance Of Interstitial Cells Of Cajal And Smooth Muscle In Diabetic Gastroparesis Rat's

Gastric neuromuscular dysfunction occurs in up to 30-50% of diabetes patients. Symptoms of diabetic gastropathy may include dysphagia,heartburn,nausea and vomiting.Gastroparesis seriously affects quality of life.there is deterioration in glycemic control,and incapacitating symptoms such as malnutrition,water and electrolyte imbalance and aspiration may occur.Diabetic gastropathy and gastroparesis,including impaired fundic and pyloric relaxation and impaired electrical pacemaking,are generally considered to be the result of systemic and/or enteric neuropathies;however,the pathophysiology of those disorders is not fully understood.ICC are responsible for the generation of electrical slow wave activity that determines frequency and propagation of peristaltic contractions.Numerous physiological studies have demonstrated that electrical pacemaking and motor neurotransmission in the stomach depend on the function of interstitial of Cajal.Multipolar ICC,which form two-dimensional networks in the myenteric region of the gastric corpus and antrum,have been identified as the source of electrical slow waves that underlie the phasic contractions of gastric musculature. Several motor disorders of the gastrointestinal tract show disruption of ICC networks including hypertrophic pyloric stenosis,Hischsprung's disease,and intestinal pseudo-obstruction.Mitochondria was organelle for energy transform. It can maintain the energy metabolism of cell and the structure and the function. Mitochondria contain their own DNA(mtDNA) and replication , transcription and translation system differented from nuclear DNA. Mitochondrial DNA(mtDNA) consist of 16596bp closed-loop doublestranded DNA which encodes 13 polypeptides of oxidative phosphorylation.The major function of mitochondria in human cells is to provide more than 90% ATP. The three largest subunits of cytochrome c oxidases (COX) are encoded by mitochondria DNA. COX is the terminal complex of the mitochondria respiratory chain. It is located in the mitochondrial inner membrane where it transfers electrons from ferrocytochrome c to molecular oxygen,to be used for ATP synthesis,ATP was the major link between mitochondrial function and slow wave,Pacemaking in ICC dependa upon calium handling by endoplasmic reticulun and mitochondrial.Objective: (1) To study the effect of motichondrial on networks of interstitial cells of cajal in diabetic gastroparesis rat ,gastric motility in diabetes rat; (2)To study the effect of apoptosis and its regulating gene in diabetic gastroparesis rats. (3) To study the change of expressions of mtDNA encoding COX genes(COX â… , COX â…¡ and COX â…¢ subunits) of ICC in diabetic gastroparesis rats and to explore the relationship between the damages of structure and function and to explain the mechanism of the energy metabolism disorder of mitochondria and the damages of cells.Methods: (1) Made of diabetic model: 120 Wistar rats were divided into two groups randomizely: diabetes group and control group. Diabetes group were intraperitoneal injected streptozotocin at a dose of 60mg/kg, control group were injected saline. Electrodes of control and diabetic group rats placed in antrum and gastric-electrical activities were recorded after 3 months. Emptying of stomach was measured with blue methylene.(2)The changes of networks ICC in diabetic rat by immuneohistochemical. ICC microstructure were observed by electrictelescope.(3) ICC mitochondrial membrane potential in diabetic rats antrum were examined by laser scanning confocal microscopy.(4)Firstly,Using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL),to observed the density and distribution of apoptosis cells in situ.secondly to study the expression status of apoptotic regulating gene bcl-2,Bax,caspases 3 in diabetic gasrtroelectric dysrhythm rats by Western-blot and immohistochemistry; (5) Gastrointestinal double labeling with c-Kit and COX I,II antibodies in diabetic gastroparesis rat were detected with immohistochemistry confocal micrographs. The changes of expressions of...