Kohsaka S, Mita K, Suda H, Matsuyama M, Tsukada Y
Neurochem Res. 1985 Sep;10(9):1299-310. doi: 10.1007/BF00964848.
Effects of a glycoprotein synthesis inhibitor on myelination were investigated in rat cerebellum. The glycoprotein synthesis inhibitor, tunicamycin (TM), was injected intracranially into newborn rats. The activity of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) in the cerebellum was significantly reduced in 2-week-old animals and was restored to the normal level by age 3 weeks. When TM was injected into newborn rats every 3-4 days for a total of 6 times, CNPase activity was still low at 3 and 4 weeks. Immunohistochemical stainings for CNPase and myelin-associated glycoprotein (MAG) were performed on paraffin sections of multiple-TM-injected cerebellum at 3 weeks. The intensity of the staining with MAG antiserum in the white matter was clearly decreased in TM-treated cerebellum compared with the control. The myelin in the granule cell layer was poorly stained with CNPase antiserum in TM-treated cerebellum. Subcellular fractionation was carried out and the CNPase activity in each fraction was measured. The CNPase activity in the myelin fraction (P2A) from the TM-treated cerebellum was significantly lower than that in the control. In contrast, the activity in the synaptosomal (P2B) and microsomal (P3) fractions from the multiple-TM-injected cerebellum was higher than in those from the controls. Polyacrylamide gel electrophoretic patterns of the P2A fractions were analyzed. The P2A fraction from TM-treated cerebellum contained less Wolfgram protein than the control. These results suggest that glycoprotein synthesis plays certain roles in myelination in the central nervous system.
在大鼠小脑中研究了一种糖蛋白合成抑制剂对髓鞘形成的影响。将糖蛋白合成抑制剂衣霉素（TM）颅内注射到新生大鼠体内。在2周龄的动物中，小脑中2',3'-环核苷酸3'-磷酸二酯酶（CNPase）的活性显著降低，并在3周龄时恢复到正常水平。当每3 - 4天给新生大鼠注射一次TM，共注射6次时，在3周和4周时CNPase活性仍然很低。在3周时，对多次注射TM的小脑石蜡切片进行CNPase和髓鞘相关糖蛋白（MAG）的免疫组织化学染色。与对照组相比，TM处理的小脑白质中MAG抗血清的染色强度明显降低。在TM处理的小脑中，颗粒细胞层的髓鞘用CNPase抗血清染色较差。进行亚细胞分级分离并测量各分级中的CNPase活性。来自TM处理小脑的髓鞘分级（P2A）中的CNPase活性明显低于对照组。相反，多次注射TM的小脑突触体（P2B）和微粒体（P3）分级中的活性高于对照组。分析了P2A分级的聚丙烯酰胺凝胶电泳图谱。来自TM处理小脑的P2A分级所含的沃尔夫拉姆蛋白比对照组少。这些结果表明糖蛋白合成在中枢神经系统的髓鞘形成中起一定作用。
