PRESERVATION OF MYELIN LAMELLAR STRUCTURE IN THE ABSENCE OF LIPID

Open Access
Publisher Website
Google Scholar
Abstract
The fine structure of myelin was studied in glutaraldehyde-fixed rat sciatic nerves depleted of lipid by acetone, chloroform:methanol (2:1 v/v), and chloroform:methanol: concentrated HC1 (200:100:1, v/v/v). One portion of each of these nerves, plus the extracts, was saponified and analyzed by gas-liquid chromatography for fatty acids. The remainder of each nerve was stained in osmium tetroxide in CCl4 (5g/100cc) and embedded in Epon 812. Thin sections, examined in the electron microscope, revealed the preservation of myelin lamellar structure with a 170 A periodicity in nerves depleted of 98% of their lipids. Preservation of myelin lamellar structure depended on glutaraldehyde fixation and the introduction of osmium tetroxide in a nonpolar vehicle (CCl4) after the lipids were extracted. The periodic lamellar structure in electron micrographs of myelin depleted of lipid, results from the complexing of osmium tetroxide, plus uranyl and lead stains, with protein.