Loike J D, Kozler V F, Silverstein S C
J Biol Chem. 1979 Oct 10;254(19):9558-64.
Resident and thioglycollate-elicited macrophages maintained in culture for 24 h contain approximately 5 x 10(-16) and 12 x 10(-16) mol of ATP per cell, respectively. During particle ingestion, the levels of ATP in these cells did not change. However, the specific activity of ATP extracted from macrophages labeled with [32P]Pi during phagocytosis was 40% lower than ATP extracted from control cells. These results suggested that macrophages contain a high energy phosphate reservoir, in addition to the ATP pool(s). A search for such a reservoir led to the identification of creatine phosphate in both resident and thioglycollate-elicited macrophages at concentrations that are in 3- to 5-fold-molar excess over ATP. Creatine phosphate levels in phagocytosing resident macrophages decreased by 45%, while creatine phosphate levels in phagocytosing thioglycollate-elicited macrophages did not change. Creatine phosphate turnover was measured in macrophages prelabeled with [14C]creatine. Over 90% of the intracellular label was in the form of creatine phosphate. During phagocytosis, there was a 40% decrease in intracellular [14C]creatine phosphate in both resident and thioglycollate-elicited macrophages. These results indicate that creatine phosphate turns over more rapidly during phagocytosis and replenishes the ATP consumed.
在培养中维持24小时的驻留巨噬细胞和巯基乙酸盐诱导的巨噬细胞，每细胞分别含有约5×10⁻¹⁶摩尔和12×10⁻¹⁶摩尔的ATP。在颗粒摄取过程中，这些细胞中的ATP水平没有变化。然而，在吞噬过程中用[³²P]Pi标记的巨噬细胞中提取的ATP的比活性比从对照细胞中提取的ATP低40%。这些结果表明，巨噬细胞除了ATP池外，还含有一个高能磷酸盐储备库。对这样一个储备库的寻找导致在驻留巨噬细胞和巯基乙酸盐诱导的巨噬细胞中都鉴定出磷酸肌酸，其浓度比ATP高3至5倍摩尔过量。吞噬驻留巨噬细胞中的磷酸肌酸水平下降了45%，而吞噬巯基乙酸盐诱导的巨噬细胞中的磷酸肌酸水平没有变化。用[¹⁴C]肌酸预标记的巨噬细胞中测量了磷酸肌酸的周转。超过90%的细胞内标记物是以磷酸肌酸的形式存在。在吞噬过程中，驻留巨噬细胞和巯基乙酸盐诱导的巨噬细胞中的细胞内[¹⁴C]磷酸肌酸都下降了40%。这些结果表明，磷酸肌酸在吞噬过程中周转更快，并补充消耗的ATP。
