title: A positive correlation between catalase activity and ascorbate uptake in the tissues of guinea pigs and cultured cells of mammals.
abstract: We recently reported that the concentration of supplemental ascorbate which inhibits cell growth is positively related to intracellular catalase activity. It is assumed that the cells with high catalase activity are resistant to high concentrations of ascorbate since catalase can decompose hydrogen peroxide (H2O2) induced by the auto-oxidation of ascorbate in cultured medium. In this study, we investigated whether intracellular catalase activity affects the uptake of ascorbate into animal tissue and cultured cells. Ascorbate concentrations in the tissues of guinea pigs and various cultured cells, with and without supplementation of ascorbate, were determined to evaluate the efficiency of ascorbate uptake. We found a positive correlation between the efficiency of ascorbate uptake and catalase activity in various tissues of guinea pigs (r = 0.767, p < 0.05). Furthermore, a positive correlation between the two was also found in various species of cultured cells. This study indicates that tissues and cells with higher efficiency of ascorbate uptake are required for higher catalase activity, presumably for the decomposition of H2O2 from ascorbate.
authors.affiliation: Department of Nutrition and Food Science, Ochanomizu University, Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Nemoto
authors.forename: M
authors.initials: M
authors.lastname: Otsuka
authors.forename: N
authors.initials: N
authors.lastname: Arakawa
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism*; D001692:Biological Transport; D002374:Catalase / Q000378:metabolism*; D002460:Cell Line; D006168:Guinea Pigs; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D007421:Intestine, Small / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D015473:Leukemia, Promyelocytic, Acute; D008099:Liver / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D016716:PC12 Cells; D051381:Rats; D014407:Tumor Cells, Cultured
chemical_list: D006861:Hydrogen Peroxide; D002374:Catalase; D001205:Ascorbic Acid