OBJECTIVE: To investigate the effect of the nerve growth factor (NGF), which is isolated and purified from the venom of Naja naja atra, on expression of GAP-43 in dorsal root ganglia (DRG) removed partially from cat. METHODS: A total of 45 adult male cats (rhizotomy of unilateral L1-Ls, L7-S2 dorsal root, leaving L6 as a spared dorsal root in 45 cats allowed to survive 3 days, 6 days, 12 days respectively) were equally divided into 3 groups based on the dose of using the drug: low-dosage group (1 microg/kg), high-dosage group (2 microg/ kg), normal saline control group (0. 1 mL/kg), with using immunohistochemical reaction to detect the GAP-43 of L6 DRG, count the GAP-43-positive large, medium-small neurons. RESULTS: The results were as follows: After the operation, GAP-43 positive products were mainly distributed in nucleus of large neurons and cytoplasm of medium-small neurons. The expressions of GAP-43 positive products in treatment group and control group were detected at day 3, reached the highest level on the 6th day and began to decrease on the 12th day. The number of GAP-43 positive medium-small neurons of the operated side DRG in treatment group increased more apparently than that of control group, the high-dosage group was significantly (P<O. 01) more than that of other groups, especially on day 6, but the number of large neurons did not change prominently. CONCLUSION: The above results indicate that NGF can effectively induce the synthesis of GAP-43 in medium-small neurons, which enhances the spared root's collateral sprout, the regeneration is related to NGF dosage.
OBJECTIVE: To investigate the effect of the nerve growth factor (NGF), which is isolated and purified from the venom of Naja naja atra, on expression of GAP-43 in dorsal root ganglia (DRG) removed partially from cat. METHODS: A total of 45 adult male cats (rhizotomy of unilateral L1-Ls, L7-S2 dorsal root, leaving L6 as a spared dorsal root in 45 cats allowed to survive 3 days, 6 days, 12 days respectively) were equally divided into 3 groups based on the dose of using the drug: low-dosage group (1 microg/kg), high-dosage group (2 microg/ kg), normal saline control group (0. 1 mL/kg), with using immunohistochemical reaction to detect the GAP-43 of L6 DRG, count the GAP-43-positive large, medium-small neurons. RESULTS: The results were as follows: After the operation, GAP-43 positive products were mainly distributed in nucleus of large neurons and cytoplasm of medium-small neurons. The expressions of GAP-43 positive products in treatment group and control group were detected at day 3, reached the highest level on the 6th day and began to decrease on the 12th day. The number of GAP-43 positive medium-small neurons of the operated side DRG in treatment group increased more apparently than that of control group, the high-dosage group was significantly (P<O. 01) more than that of other groups, especially on day 6, but the number of large neurons did not change prominently. CONCLUSION: The above results indicate that NGF can effectively induce the synthesis of GAP-43 in medium-small neurons, which enhances the spared root's collateral sprout, the regeneration is related to NGF dosage.