Changes of diaphragmatic function and morphologic features in diabetic rats / 中国病理生理杂志

ABSTRACT

AIM: To evaluate the changes of diaphragm contractile properties and morphologic features in experimental diabetic rats. 糤THZ]METHODS: METHODS: Diaphragm contractility was assessed by twitch kinetics, maximal tetanic force (P 0) , tension-frequency relationship and fatigue index (FI) in vitro diaphragm strip preparations of 4th week diabetic Wistar rats, and compared with that of the control group. The structure of diaphragm was analysed in diabetic rats and control with Hematoxyline and eosin staining, Heidenhain staining and enzymatic histochemistry. RESULTS: The twitch (Pt), contraction time (CT), half relaxation time (RT 1/2 ) and FI decreased significantly in diabetic group as compared with the control group. There was no difference in Po between the two groups. The tension of diabetic diaphragm at frequencies of 25,50,75,100 and 125 Hz was significantly decreased compared with that of the normal rats. After diaphragm bundles were subjected to fatiguing stimulations and incubated with aminophylline at 250 mg/L for 30 minutes, the tension of diabetic diaphragm decreased remarkably at both high and low frequencies in comparison with that of the normal rats. In addition, the activity and optical density of ?-phosphoglycerol dehydrogenase in diaphragm from diabetic rats were significantly lower than that from control rats ( P