Cerebral subcellular distribution of CDP-choline and/or its metabolites after oral administration of methyl-14C CDP-choline.
Distribution of radioactivity in subcellular components of a cerebral extract after oral administration of methyl-14C labelled cytidine diphosphate choline (CDP-choline, citicoline, Somazina) was analyzed. Animals were decapitated 24 h after the administration and the brain immediately removed and gently homogenized in a buffer solution. The homogenate was fractionated by differential centrifugation and the protein concentration and the radioactivity were measured in each precipitate as well as in the final supernatant. Radioactivity was found to be associated mainly with membranous microsomal precipitate and with cytoplasmic membrane precipitate. Alternatively, materials sedimenting between 500 X g and 20,000 X g were fractionated in a density gradient centrifugation. Fractions were screened for enzymatic activities as indicators of cytoplasmic membrane, mitochondria, lysosomes, microsomes and synaptosomes. Radioactivity was found to be associated with cytoplasmic and microsomal membrane fractions. Identification of some fractions as enriched in synaptosomes also accumulating radioactivity, as well as the possible incorporation of the radioactivity to choline and phosphorylcholine cerebral pools are discussed.
D000284:Administration, Oral; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002498:Centrifugation; D002499:Centrifugation, Density Gradient; D002794:Choline / Q000031:analogs & derivatives*; D003566:Cytidine Diphosphate Choline / Q000378:metabolism*; D008297:Male; D051381:Rats; D013047:Specific Pathogen-Free Organisms; D013347:Subcellular Fractions / Q000378:metabolism*
D003566:Cytidine Diphosphate Choline; D002794:Choline