Premium
MYELIN SYNTHESIS IN VITRO: A COMPARATIVE STUDY OF CENTRAL AND PERIPHERAL NERVOUS TISSUE
Author(s) -
Rawlins F. A.,
Smith Marion E.
Publication year - 1971
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1971.tb09592.x
Subject(s) - myelin , central nervous system , peripheral nervous system , spinal cord , biology , sciatic nerve , endocrinology , nervous tissue , medicine , lecithin , myelin basic protein , nervous system , biochemistry , chemistry , anatomy , neuroscience
— Brain, spinal cord and sciatic nerve from rats at different ages were incubated for 2 h in a medium containing [ 14 C]acetate and [ 14 C]leucine as the precursors for synthesis of lipids and proteins. Myelin was purified from the incubated tissues and the specific and total radioactivites of myelin lipids and protein were determined. The uptake of radioactive precursors decreased with increasing age up to 6 months of postnatal age, the decrease following the same pattern for the three types of myelin. After age 6 months the uptake of the protein and lipid precursors reached a plateau that persisted up to 18 months, the oldest postnatal age studied. The amount of myelin isolated and the total myelin lipids extracted from both the central and peripheral nervous systems increased continuously from age 25 days to 18 months after birth. Consequently we suggest that myelination is a process that continues during the whole life of the rat. The metabolic activity of peripheral nerve myelin was higher than myelin from the CNS at all ages studied. Although myelination in the sciatic nerve begins before that in brain and spinal cord, the three types of myelin apparently reach maturity at the same age. Lecithin exhibited the highest metabolic activity of the individual myelin lipids at all ages in both the central and peripheral nervous system. The metabolic activity of cholesterol in myelin from the 25‐day‐old rats was similar to that of lecithin but decreased to very low levels in myelin from the 18‐month‐old rats.