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DETECTION OF MYELIN IN THE OPTIC NERVE OF YOUNG RATS BY SEDIMENTATION EQUILIBRIUM IN A CsCl GRADIENT 1
Author(s) -
Detering Nancy K.,
Wells M. A.
Publication year - 1976
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.1471-4159.1976.tb04472.x
Subject(s) - galactolipid , isopycnic , chemistry , chromatography , phospholipid , ultracentrifuge , myelin , density gradient , white matter , optic nerve , chloroform , tris , biochemistry , centrifugation , anatomy , membrane , biology , endocrinology , medicine , physics , radiology , quantum mechanics , magnetic resonance imaging , central nervous system
—A method is described for detecting myelin in small amounts of tissue by density criteria. Samples are homogenized in 0.926 m ‐CsCl, 10 m m ‐Tris‐HCl, (pH 7.4), 5 m m ‐Ca 2+ solution and centrifuged to equilibrium at 52,000 rev./min and 4°C in the AN‐F rotor of the Model E analytical ultracentrifuge. Homogenates of white matter show a band of material in the density range of 1.20–1.130 g/ml, whereas gray matter homogenates do not show a band of material in this density region. A preparative method is described for isolating the material banding in the region of 1.120–1.130 g/ml from optic nerve homogenates of 21‐day old rats. This material has (1) a protein content of 22–24%, (2) an enzymatic activity for 2′,3′‐cyclic nucleotide phosphohydrolase of 13.1 μmol/min per mg protein and (3) a phospholipid‐cholesterol‐galactolipid molar ratio of 100:100:48. Plasmalogen accounted for 22% of the phospholipid, and sulfatide accounted for 31% of the galactolipid. This material is 85% soluble in chloroform:methanol (2:1. v:v). Developmental studies indicate that this myelin material can first be detected in the optic nerve from an 11‐day‐old rat.