A POSITIVE CORRELATION BETWEEN CATALASE ACTIVITY AND ASCORBATE UPTAKEIN THE TISSUES OF GUINEA-PIGS AND CULTURED-CELLS OF MAMMALS

We recently reported that the concentration of supplemental ascorbate which inhibits cell growth is positively related to intracellular cata lase activity. It is assumed that the cells with high catalase activit y are resistant to high concentrations of ascorbate since catalase can decompose hydrogen peroxide (H2O2) induced by the auto-oxidation of a scorbate in cultured medium. In this study, we investigated whether in tracellular catalase activity affects the uptake of ascorbate into ani mal tissue and cultured cells. Ascorbate concentrations in the tissues of guinea pigs and various cultured cells, with and without supplemen tation of ascorbate, were determined to evaluate the efficiency of asc orbate 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 stu dy indicates that tissues and cells with higher efficiency of ascorbat e uptake are required for higher catalase activity, presumably for the decomposition of H2O2 from ascorbate.