Ascorbic acid uptake to isolated nerve terminals and secretory granules from ox neurohypophyses.
Isolated nerve terminals (neurosecretosomes) from cow neurohypophyses accumulated radioactivity when they were incubated with L[14C]-ascorbic acid in an ionic medium dominated by NaCl. Uptake of radioactivity was saturable with ascorbic acid concentration. Replacement of Na+ with Li+ in the incubation medium or presence of ouabain inhibited the accumulation. Isolated, purified cow neurosecretory granules contained 14 +/- 2 nmol ascorbate (n = 10) per mg of protein. When such granules were incubated with L[14C]-ascorbic acid in a KCl dominated medium, they took up radioactivity slowly. The accumulation was not saturable with ascorbic acid concentration and was not influenced by the presence of Mg2+ATP.
D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism*; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D003470:Culture Media; D003594:Cytoplasmic Granules / Q000378:metabolism*; D005260:Female; D006863:Hydrogen-Ion Concentration; D008928:Mitochondria / Q000378:metabolism; D010904:Pituitary Gland, Posterior / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism
D003470:Culture Media; D001205:Ascorbic Acid