title: Stabilization of ascorbic acid and norepinephrine in vitro by the subcellular fractions of rat cerebral cortex.
abstract: The effect of various subcellular fractions of rat cerebral cortex on the autoxidation of ascorbic acid and norepinephrine in a physiological salt solution, pH 7.4, was investigated. The rate of the two reactions was determined spectrophotometrically at 265 and 480 nm, respectively. The cytoplasmic, microsomal, crude mitochondrial fractions and a soluble phase of mixed subcellular origin (100,000 g supernatant) were tested in an assay system in which the final dilution of the cellular components was in the 10(3) to 10(6) range. The samples were heat-treated (30 min at 100 degrees C) and dialyzed (50,000 mol.wt. cut-off) prior to analysis. The preparations produced approximately 80% inhibition at 10(3)-fold dilution and marginal inhibition at 10(5)-fold dilution, except the microsomal preparation, which was a considerably weaker inhibitor in the norepinephrine autoxidation test. The study shows that all three major subcellular compartments of the rat cerebral cortex have macromolecules with a high level of heat-stable autoxidation-inhibiting activity.
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000032:analysis*; D001205:Ascorbic Acid / Q000378:metabolism*; D002540:Cerebral Cortex / Q000032:analysis* / Q000378:metabolism; D003593:Cytoplasm / Q000032:analysis; D008297:Male; D008861:Microsomes / Q000032:analysis; D008928:Mitochondria / Q000032:analysis; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D013347:Subcellular Fractions / Q000032:analysis / Q000378:metabolism
chemical_list: D000975:Antioxidants; D001205:Ascorbic Acid; D009638:Norepinephrine