ABSTRACT
Objective To evaluate the changes in myocardial glucose transporter 4 ( GLUT4 ) membrane translocation in the rats with high-level spinal cord injury ( SCI ) . Methods Thirty-six clean-grade healthy adult male Sprague-Dawley rats, weighing 250-300 g, were divided into 3 groups using a random number table method: control group (group C, n=6), sham operation group (group S, n=6) and high-level SCI group (group SCI, n=24). The model of SCI was established by a modified Allen's method in anesthetized rats. The spinal cord was only exposed in group S. Six rats were selected in C and S groups and at 4, 12, 24 and 48 h after SCI ( T1-4 ) in group SCI, and blood samples were taken from the abdominal aorta to measure the activities of serum creatine kinase and creatine kinase isoenzyme-MB. The rats were then sacrificed, and myocardial specimens were collected for microscopic examination of the ultra-structure ( with a transmission electron microscope) and for determination of ATP weight ratio, phosphoryla-tion of insulin receptor substrate-1 tyrosine and expression of GLUT4 in cell membrane ( by Western blot) . Results Compared with C and S groups, the serum creatine kinase and creatine kinase isoenzyme-MB ac-tivities were significantly increased at T1-4 , the ATP weight ratio was decreased, the expression of GLUT4 in myocardial cell membrane was down-regulated, the expression of phosphorylated insulin receptor sub-strate-1 tyrosine in myocaradium was down-regulated at T2,3 (P＜0. 05), and the pathological changes of myocardial tissues were found in group SCI. There was no significant difference in the indexes mentioned a-bove between group C and group S ( P＞0. 05) . Conclusion The mechanism of myocardial energy metabo-lism disorder may be related to the reduced membrane translocation of GLUT4 in the rats with high-level SCI.