| Spinal cord injury is a serious disease in China, and has a high incidence of disease, death rate and incomplete rate. NGF plays an important role on the cure of spinal cord injury. Insulin - like growth factor I (IGF- 1) , as one of the NGF, has abroad biological func-tions, and has an important therapy effects on the ischemia of brain tissues. But the reports about the therapy effects on the SCI have not been seen in China. The author gave local injections of IGF - 1 to the rat SCI model. Measured the hind - limb motor functions of rats ant 48h after the operation. Counted the number of neuron cell. Observed the expression of Bel - 2 protein. And examine the effects of IGF - 1 on paraplegia and neuron cell after SCI.Materials and Methods1. experimental groupWe selected 22 Wistar rats, male or female are both allowed. Their weights are between 240-260g. Divided into 3 groups. 8 rats re-ceived IGF - 1.8 rats received 0.9% NS. 6 rats received insulin, check the function of hind - limb, and counted the motor cell of spinal cord and the expression of Bel - 2 proteins.2. the foundation of SCI modelApply "Allen* s shock" to hurt the spinal cord. After operation IGF - 1 or insulin or 0. 9% NS were injected into the rats of each groups.3. preparation of pathology sampleAll rats were deeply anesthetized with 10% chloral hydrate (2ml/kg). Spile the left ventricle and cut the right atria. First, all the rats were perfused by 250ml 0.9 NS and then by the 4% formalde-hyde 250ml. The spinal cord was taken off from the rats and fixed with 4% formaldehyde. And the samples were embedded in paraffin. Transverse sections were cut to a thickness of 4 um. For quantification of the number of motor neuron cells, motor anterior horn cells were counted in 6 sections at a magnification of 200, and values were aver-aged.4. measure index and method (1) neurologic assessmentHind - limb motor function was scored at 6,24 and 48 hours after the operation by using the modified Tarlov Scale (0 = no movement, 1 = slight movement, 2 = sit with assistance, 3 = sits alone, 4 = weak hop, 5 = normal hop).( 2 ) the number of motor neuron cellsAfter HE staining, the 6 sections from every sample were coun-ted, and the number of motor neuron cells were calculated and the values were averaged.( 3) immunohistochemical staining for Bel - 2 proteinsApply immunohistochemical SP method, and processed as the demonstration of the factory to count the number of the neuron cell which staining by the Bel - 2 proteins.5. statistical analysisStatistical analysis of the neurologic scores was preformed with the Mann Witney U test. And other data are presented as means ?SD. One way analysis of variance and the Scheffe' multiple compari-son test were used to compare the multi group variables.Results1. neurologic assessmentParaplegia ( score = 0) developed in 4 of 8 rats in the control group within 6 hours after the operation. The condition of the other4 rats in the control group had deteriorated to paraplegia by 24 and 48 hours after the operation. In contrast, all the rats treated with IGF - 1 maintained hind - limb motor function scores of 4 or 5 for 48 hours af-ter the operation. Although 2 of 6 rats treated with insulin maintained hind - limb motor function scores of 4 or 5 for 48 hours after the opera-tion, paraplegia developed within 24 hours after the operation in the other 4 rats.2. the number of spinal cord anterior horn motor neuron cellsIn the control rats, the segment that had been subjected to spinal cord injury showed server neuronal damage as evidenced by reduced numbers of motor neuron cells, disappearance of Nissl bodies and nu-clei in the remaining motor neuron cells and vacuolation of gray mat-ter. In contrast, the rats treated with IGF - 1 showed almost intact -looking light microscopic findings of the involved spinal cord segment. The rats treated with insulin showed microscopic abnormal in the in-volved spinal cord segment similar to those observed in the control rats, althoug... |
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