Development investigation for enhancement of regeneration and amelioration of function of the damaged peripheral nerves by medical regulation of neurotrophin synthesis.

(1)4-甲基儿茶酚（4-MC）对糖尿病或丙烯酰胺诱发的周围神经病变神经元功能障碍的持续改善链脲佐菌素（STZ）诱发的糖尿病大鼠表现出坐骨神经运动神经传导速度（MNCV）、有髓轴突直径和神经生长因子（NGF）含量的降低。注射STZ 4周后开始的4-MC治疗导致糖尿病大鼠的所有这些损伤得到改善。在丙烯酰胺（ACR）诱导的大鼠神经病变中，当ACR和4-MC联合腹腔注射时，临床症状得到改善，坐骨神经中NGF含量增加，MNCV加快，有髓纤维密度增加，这些结果表明NGF水平降低可能参与了糖尿病和ACR诱导的神经病变的发病机制，4-MC治疗可能是一种有效的治疗方法。(2)脑源性神经营养因子（BDNF）和神经营养素-3（NT-3）特异性抗体的制备定量检测其在周围神经再生和功能修复中的作用是必要的。我们成功地在鸡中培养了特异性识别BDNF或NT-3的抗体。使用这些抗体的双位点酶免疫分析可以检测低至几pg/ml浓度的BDNF和/或NT-3。(3)鸡背根神经节（DGR）培养神经元中BDNF表达的调节最近的报道定位于鸡胚DRG培养神经元中的BDNF mRNA，这是已知对BDNF有反应的。为了估计BDNF在DRG神经元中表达的生理作用，我们研究了去极化过程中BDNF样免疫反应性的变化，发现它引起BDNF蛋白表达的短暂降低。提示在外周感觉系统成熟过程中，刺激传递后去极化抑制了DRG神经元BDNF的合成。

(1) EFFECTIVE IMPROVEMENT ON NEURONAL DYSFUNCTION BY ADMINISTRATION OF 4-METHYLCATECHOL (4-MC) IN DIABETIC OR ACRYLAMIDE-INDUCED PERIPHERAL NEUROPATHY.Streptozotocin (STZ) -induced diabetic rats showed a reduction in motor nerve conduction velocity (MNCV), myelinated axon diameter, and nerve growth factor (NGF) content in the sciatic nerve. 4-MC treatment started 4 weeks after the STZ injection resulted in improvements on all of these damages in diabetic rats. In acrylamide (ACR) -induced neuropathy, when ACR and 4-MC were coadministered intraperitoneallys, improved clinical signs, and more NGF content in the sciatic nerves, faster MNCV,and greater myelinated fiber density than in rats given ACR alone were found. These findings suggest that a decreased NGF level may be involved in the pathogenesis of diabetic and ACR-induced neuropathies and that 4-MC treatment could be a useful therapy.(2) PREPARATION OF ANTIBODIES SPECIFICALLY RECOGNIZE BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) AND NEUROTROPHIN-3 (NT-3).Quantitative methods to detect respective neurotrophins are necessary to evaluate theirroles in regeneration and functional repair of perigheral nerves. We succeeded to raise antibodies in chicken specifically recognize BDNF or NT-3. Two-site enzyme immunoassaies using these antibodies could detect BDNF and/or NT-3 as low as a concentration of a few pg/ml.(3) REGULATION OF BDNF EXPRESSION IN NEURONS CULTURED FROM CHICK DORSAL ROOT GANGLIA (DGR).Recent reports localize BDNF mRNA in the neurons cultured from chick embryo DRG,which are known responsive to BDNF.To estimate physiological roles of BDNF expression in the DRG neurons, we investigated changes of BDHF-like immunoreactivity during depolarization, and found that it caused a transient decrease in expression of BDNF protein. This suggests that stimuli-transmission followd by depolarization suppresses BDNF synthesis in DRG neurons during maturation of peripheral sensory system.