许旺细胞源神经营养因子受体在脊髓组织中的分布研究

Exploration of the receptor of Schwann cell derived neurotrophic factor in rat spinal cord

目的 探讨脊髓组织中是否存在许旺细胞源神经营养因子 (SDNF)受体及其在亚细胞水平的分布情况。 方法 应用放射性配体结合法检测脊髓中1 2 5 I- SDNF的特异性结合。 结果 (1)脊髓组织 1 2 5 I- SDNF特异结合的最大容量 (Bmax)为 (2 .86± 0 .2 2 ) fmol/ mg蛋白 ;平衡解离常数 (Kd)为(4 9.4± 6 .5 ) pmol/ L;(2 )动力学分析显示 K1 为 (9,2± 0 .7)× 10 7M- 1 × min- 1 ,K- 1 为 (4 .2± 0 .5 )× 10 - 3min- 1 ;(3)特异性分析表明对 SDNF高度特异性 ;(4 )亚细胞分布 :特异结合位点以微粒体膜含量最高。 结论 脊髓中存在 SDNF的受体 ,表明脊髓为

Objective To explore whether there exists Schwann cell derived neurotrophic factor(SDNF) receptor Methods SDNF binding sites in rat spinal cord were studied using 125 I SDNF as a radioligand (radioligand binding assays) Results ①The maximal binding capacity (B max ) of SDNF was (2 86±0 22) fmol/mg protein and the equilibrium dissociation constant (Kd) was (49 4±6 5) pmol/L ②Kinetic studies revealed that the association rate constant (K 1) was (9 2±0 7) ×10 7 M 1 ×min 1 and the dissociation (K 1) (4 2±0 5)×10 3 min 1 ③Specific studies of SDNF binding sites showed that the binding sites were highly specific for SDNF ④ The subcellular distribution of SDNF was in the following descending order: microsomal>mitochondrial>cytosol>nuclear fraction Conclusion Results demonstrated the presense of SDNF receptor in the rat spinal cord, which may act as traget tissue of SDNF