Effects of glycoprotein synthesis inhibitor on myelination in rat cerebellum.
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.
S
S
Kohsaka
K
K
Mita
H
H
Suda
M
M
Matsuyama
Y
Y
Tsukada
D015087:2',3'-Cyclic-Nucleotide Phosphodiesterases / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D002531:Cerebellum / Q000254:growth & development* / Q000378:metabolism; D005944:Glucosamine / Q000031:analogs & derivatives*; D006023:Glycoproteins / Q000502:physiology*; D007124:Immunoenzyme Techniques; D009185:Myelin Proteins / Q000378:metabolism; D009186:Myelin Sheath / Q000502:physiology*; D018992:Myelin-Associated Glycoprotein; D051381:Rats; D011919:Rats, Inbred Strains; D014415:Tunicamycin / Q000494:pharmacology*
D006023:Glycoproteins; D009185:Myelin Proteins; D018992:Myelin-Associated Glycoprotein; D014415:Tunicamycin; D015087:2',3'-Cyclic-Nucleotide Phosphodiesterases; C039809:2',3'-cyclic nucleotide 2'-phosphodiesterase; D005944:Glucosamine