The Changes On The Expression Of NGF And NT-4 Following HSCI Of Adult Monkey

[Object i ve] :To explore the changes on polypeptide growth factors, including NGF and NT-4 in the ventral horn of the spinal cord and motor area of right cerebral cortex of adult monkey at different time after hemisection spinal cord injury (hSCI).[Material and Methods]: 18 healthy adult Rhesus macaques of Yunnan were randomly divided into 6 groups: sham-operated group, after hSCI 7th day group, 14th day group, 30th day group, 60th day group, 90th day group.The T10-T11 injuried segments of the spinal cord and motor area of right cerebral cortex were taked out, and fixed with 4% polymerisatum. Then put them into 20% sucrose-PBS overnight. Lastly, the spinal cord and cerebral cortex were made into frozen sections in 20um thickness. Next, anti-NGF and NT-4 serum were applied respectively with the immunohistochemical SP method to detect the distribution and expression of NGF and NT-4 in spinal cord's ventral horn and cerebral cortex's motor area at different period ater hSCI ( These sections were all selected at random ). At last, NGF and NT-4 postive neurons were observed and counted with the help of Olympus light microscope. The data of the number of positive neurons both NGF and NT-4 were analyzed by factorial ANOVA, one-way ANOVA and LSD test.[Results]: 1. NGF and NT-4 postive neurons were observed in both sham-operated group and the kinds of the operated groups, and the orientation of immunoreactivities for NGF and NT-4 mainly were in the cytoplasm. 2. After hSCI of Rhesus macaques, the postive neurons for NGF and NT-4 of untraumatic andtraumatic ventral horn of both upside and subside the lesion in the classes of the operated groups all were significantly lower than the one of sham-operated control group( P <0.05 ). Moreover, the immunoreactivities of NGF and NT-4 in the motor area of right cerebral cortex were lower than the one of sham-operated control group( P <0.05 ). 3. The expression of NGF and NT-4 protein is different at different periods. ( 1 ) NGF postive motoneurons of anterior horn had significant change between every two of both the sham-operated and operated groups (P <0.05 ), except one of between the 7th day and 14th day group( P >0.05 ). NGF postive neurons of the 7th day and 14th day group in the injuried and initial stage decreased, but ones of the 30th day suddenly increased to topmost after hSCI and they were lower than ones of sham-operated group. Then there had been gradual fall to minimum. ( 2 ) Immunoreactivities for NGF in the motor area of right cerebral cortex had been a similar tendency and the expression of NGF in the 30th day group was maximum. ( 3 ) NT-4 postive neurons were on the persistent drop after hSCI, furthermore fell to minimum. There had been a sharp rise in the 30th day, then they were on the decline after 90th day of spinal cord injury. (4 ) The postive motoneurons in the motor area of right cerebral cortex abruptly decrease to minimum. Lastly, there was a slow rise in 14th day and a sudden increase in the 60th day. The amount of postive neurons was normal on the whole following the 90th day.[Cone I us i ons]: 1. There was the expression of NGF and NT-4 protein in both the ventral horn of the spinal cord and motor area of right cerebral cortex of the sham-operated and the operated groups. The orientation of immunoreactivities for NGF and NT-4 mainly are in the cytoplasm, but the staining of the nucleus and neurite was relatively hypochromic. This hints the physiological and functional activities of ventral horn of the spinal cord and motor area of right cerebral cortex which NGF and NT-4 together participated in. 2. NGF and NT-4 of the ventral horn of the spinal cord and motor area of right cerebral cortex were all less than the sham operated control group at different period after hSCI, and they almost did not reach the topmost of the sham operated group. The therapeutic effect of the advancing primate including mankind is worse than one of the rodents. This clues the lack of polypeptide growthfactors possibly is one of the most important reasons the man hardly rehabilitates after spinal cord injury. 3. The expression of endogenous polypeptide growth factors was lest in the early days after hSCI, but it reached to topmost in the intermediate stage. Finally it was on the gradual fall during later period, even it was the expression at low level. The expression regularities of these endogenous growth factors play a significant role in the practice, and will provide valuable theoretical evidences.