The phosphogluconate pathway and synthesis of 5-phosphoribosyl-1-pyrophosphate in human fibroblasts.
The phosphogluconate pathway and synthesis of 5-phosphoribosyl-1-pyrophosphate in human fibroblasts.
复制标题
人成纤维细胞中的磷酸葡萄糖酸途径和 5-磷酸核糖基-1-焦磷酸的合成。
DOI：
10.1016/0304-4165(81)90046-5
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
Becker,MA
中科院分区：
文献类型：
--
作者：
Raivio,KO;Lazar,CS;Krumholz,HR;Becker,MA
正常成纤维细胞的磷酸葡萄糖酸途径（戊糖磷酸循环）被亚甲基蓝刺激20倍，被6-氨基烟碱酰胺抑制至基线率的14%。在葡萄糖-6-磷酸脱氢酶活性缺乏（平均为正常平均值的1.5%）的成纤维细胞中，戊糖磷酸循环不受亚甲基蓝或6-氨基烟碱酰胺的影响。在正常细胞中，亚甲基蓝和6-氨基烟酰胺引起的磷酸葡萄糖酸途径速率的显著相反变化既没有改变细胞内浓度，也没有改变5-磷酸核糖基-1-焦磷酸的生成速率。亚甲基蓝使细胞内核糖5-磷酸浓度增加（平均增加83%），而6-氨基烟碱酰胺对细胞内核糖5-磷酸浓度的影响不显著。在葡萄糖-6-磷酸脱氢酶活性不足的成纤维细胞中，在所有研究条件下，与正常细胞相比，5-磷酸核糖基-1-焦磷酸的浓度和生成速率都更高而不是更低。这些数据表明，磷酸葡萄糖酸途径的非氧化分支在为核苷酸生物合成提供5-磷酸核糖方面发挥了主要作用。戊糖磷酸供应不能被认为是成纤维细胞氧化分支的基本功能。
The phosphogluconate pathway (pentose phosphate cycle) of normal fibroblasts was stimulated 20-fold by methylene blue and inhibited to 14% of the baseline rate by 6-aminonicotinamide. In fibroblasts deficient in glucose-6-phosphate dehydrogenase activity (an average of 1.5% of normal mean), the pentose phosphate cylce was unaffected by either methylene blue or 6-aminonicotinamide. In normal cells, neither the intracellular concentration nor the rate of generation of 5-phosphoribosyl-1-pyrophosphate was altered by the marked and opposite changes in the rate of the phosphogluconate pathway caused by methylene blue and 6-aminonicotinamide. Intracellular ribose 5-phosphate concentration was increased by methylene blue (an average increase of 83%) but not significant altered by 6-aminonicotinamide. In fibroblasts deficient in glucose-6-phosphate dehydrogenase activity, the 5-phosphoribosyl-1-pyrophosphate concentration and rate of generation were higher rather than lower in comparison to normal cells under all conditions studied. The data suggest a predominant role for the nonoxidative branch of the phosphogluconate pathway in supplying ribose 5-phosphate for nucleotide biosynthesis. Pentose phosphate supply cannot be considered an essential function of the oxidative branch in fibroblasts.