Nemoto S, Otsuka M, Arakawa N
Department of Nutrition and Food Science, Ochanomizu University, Tokyo, Japan.
J Nutr Sci Vitaminol (Tokyo). 1996 Oct;42(5):387-95. doi: 10.3177/jnsv.42.387.
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.
我们最近报道,抑制细胞生长的补充抗坏血酸浓度与细胞内过氧化氢酶活性呈正相关。据推测,过氧化氢酶活性高的细胞对高浓度抗坏血酸具有抗性,因为过氧化氢酶可以分解培养基中抗坏血酸自氧化诱导产生的过氧化氢(H2O2)。在本研究中,我们调查了细胞内过氧化氢酶活性是否会影响抗坏血酸进入动物组织和培养细胞的摄取。测定了补充和未补充抗坏血酸的豚鼠组织及各种培养细胞中的抗坏血酸浓度,以评估抗坏血酸摄取效率。我们发现豚鼠各种组织中抗坏血酸摄取效率与过氧化氢酶活性之间存在正相关(r = 0.767,p < 0.05)。此外,在各种培养细胞中也发现了两者之间的正相关。本研究表明,抗坏血酸摄取效率较高的组织和细胞对于较高的过氧化氢酶活性是必需的,这可能是为了分解抗坏血酸产生的H2O2。