Newsholme P, Curi R, Gordon S, Newsholme E A
Biochem J. 1986 Oct 1;239(1):121-5. doi: 10.1042/bj2390121.
Maximum activities of some key enzymes of metabolism were studied in elicited (inflammatory) macrophages of the mouse and lymph-node lymphocytes of the rat. The activity of hexokinase in the macrophage is very high, as high as that in any other major tissue of the body, and higher than that of phosphorylase or 6-phosphofructokinase, suggesting that glucose is a more important fuel than glycogen and that the pentose phosphate pathway is also important in these cells. The latter suggestion is supported by the high activities of both glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. However, the rate of glucose utilization by 'resting' macrophages incubated in vitro is less than the 10% of the activity of 6-phosphofructokinase: this suggests that the rate of glycolysis is increased dramatically during phagocytosis or increased secretory activity. The macrophages possess higher activities of citrate synthase and oxoglutarate dehydrogenase than do lymphocytes, suggesting that the tricarboxylic acid cycle may be important in energy generation in these cells. The activity of 3-oxoacid CoA-transferase is higher in the macrophage, but that of 3-hydroxybutyrate dehydrogenase is very much lower than those in the lymphocytes. The activity of carnitine palmitoyltransferase is higher in macrophages, suggesting that fatty acids as well as acetoacetate could provide acetyl-CoA as substrate for the tricarboxylic acid cycle. No detectable rate of acetoacetate or 3-hydroxybutyrate utilization was observed during incubation of resting macrophages, but that of oleate was 1.0 nmol/h per mg of protein or about 2.2% of the activity of palmitoyltransferase. The activity of glutaminase is about 4-fold higher in macrophages than in lymphocytes, which suggests that the rate of glutamine utilization could be very high. The rate of utilization of glutamine by resting incubated macrophages was similar to that reported for rat lymphocytes, but was considerably lower than the activity of glutaminase.
对小鼠的诱导（炎症）巨噬细胞和大鼠的淋巴结淋巴细胞中一些关键代谢酶的最大活性进行了研究。巨噬细胞中己糖激酶的活性非常高，与身体任何其他主要组织中的活性一样高，且高于磷酸化酶或6-磷酸果糖激酶的活性，这表明葡萄糖是比糖原更重要的燃料，并且戊糖磷酸途径在这些细胞中也很重要。葡萄糖-6-磷酸脱氢酶和6-磷酸葡萄糖酸脱氢酶的高活性支持了后一种观点。然而，体外培养的“静止”巨噬细胞的葡萄糖利用率不到6-磷酸果糖激酶活性的10%：这表明在吞噬作用或分泌活性增加期间糖酵解速率会显著提高。巨噬细胞中柠檬酸合酶和草酰戊二酸脱氢酶的活性高于淋巴细胞，这表明三羧酸循环在这些细胞的能量产生中可能很重要。巨噬细胞中3-氧代酸辅酶A转移酶的活性较高，但3-羟基丁酸脱氢酶的活性远低于淋巴细胞中的活性。巨噬细胞中肉碱棕榈酰转移酶的活性较高，这表明脂肪酸以及乙酰乙酸可以作为三羧酸循环的底物提供乙酰辅酶A。在静止巨噬细胞培养过程中未观察到乙酰乙酸或3-羟基丁酸的可检测利用率，但油酸的利用率为每毫克蛋白质1.0 nmol/h或约为棕榈酰转移酶活性的2.2%。巨噬细胞中谷氨酰胺酶的活性比淋巴细胞高约4倍，这表明谷氨酰胺的利用率可能非常高。静止培养的巨噬细胞对谷氨酰胺的利用率与报道的大鼠淋巴细胞的利用率相似，但远低于谷氨酰胺酶的活性。
