title: Density and protein profiles of myelin from two regions of young and adult rat CNS.
abstract: Myelin, isolated from forebrain and spinal cord of young and adult rats, was distributed by zonal centrifugation on linear (0.32--1.00 M) sucrose gradients in a bell-shaped mode. The peak position of forebrain myelin shifted from the density of 0.58 M sucrose in young animals to that of 0.67 M sucrose in adult rats, while in spinal cord no such pronounced shift was noticed (approximately 0.58 M sucrose). Morphologically, the preparations appeared very similar across the density ranges. Specific activities of acetylcholinesterase were substantially below the total homogenates, while those of 2', 3'-cyclic nucleotide 3'-phosphohydrolase were higher in all fractions, except in the light myelin subfractions from adult spinal cord. Basic proteins decreased from the light to the heavier fractions; higher molecular weight proteins increased, together with proteolipid protein, which in spinal cord reached a plateau and in forebrain decreased towards the heavy side. The ratio of the small basic protein/large basic protein showed higher values in the light myelin subfractions in the regions and ages examined, pointing to a higher degree of maturation.
mesh_terms: D015087:2',3'-Cyclic-Nucleotide Phosphodiesterases / Q000032:analysis; D000110:Acetylcholinesterase / Q000032:analysis; D000367:Age Factors; D000818:Animals; D001921:Brain / Q000201:enzymology; D001923:Brain Chemistry; D002501:Centrifugation, Zonal; D008970:Molecular Weight; D009185:Myelin Proteins / Q000032:analysis*; D009186:Myelin Sheath / Q000032:analysis*; D051381:Rats; D013116:Spinal Cord / Q000032:analysis* / Q000201:enzymology
chemical_list: D009185:Myelin Proteins; D000110:Acetylcholinesterase; D015087:2',3'-Cyclic-Nucleotide Phosphodiesterases