Williams G T, Lau K M, Coote J M, Johnstone A P
Exp Cell Res. 1985 Oct;160(2):419-26. doi: 10.1016/0014-4827(85)90189-2.
The NAD concentration in eukaryotic cells is an important parameter for many aspects of metabolism including differentiation. As reported by other workers, the NAD content of resting human peripheral blood lymphocytes was low and increased dramatically over a period of 3 days after stimulation with the mitogen phytohemagglutinin (PHA). However, simultaneous measurement of the mean cell volumes showed that the average NAD concentration in fresh quiescent lymphocytes (401 +/- 128 microM) (SD, n = 7) was similar to that observed for other cell types. Furthermore, because of the increase in cell volume which occurred on mitogen stimulation, the NAD concentration in stimulated lymphocytes was only 2-3-fold higher than in fresh resting cells. This increase was also observed in lymphocytes incubated without mitogen and was apparently due to the level of NAD precursors in the culture medium and serum supplement. Hence, the NAD concentration in resting and stimulated lymphocytes is comparable to that of other eukaryotic cells and the variations in NAD content reported earlier have been widely misinterpreted.
真核细胞中的NAD浓度是包括分化在内的许多代谢方面的一个重要参数。正如其他研究者所报道的，静息的人外周血淋巴细胞的NAD含量较低，在用有丝分裂原植物血凝素（PHA）刺激后的3天内显著增加。然而，同时测量平均细胞体积表明，新鲜静止淋巴细胞中的平均NAD浓度（401±128微摩尔）（标准差，n = 7）与其他细胞类型中观察到的浓度相似。此外，由于有丝分裂原刺激时细胞体积增加，受刺激淋巴细胞中的NAD浓度仅比新鲜静止细胞高2至3倍。在没有有丝分裂原的情况下培养的淋巴细胞中也观察到这种增加，这显然是由于培养基和血清补充物中NAD前体的水平所致。因此，静止和受刺激淋巴细胞中的NAD浓度与其他真核细胞相当，早期报道的NAD含量变化被广泛误解了。
