Iles R A, Stevens A N, Griffiths J R, Morris P G
Biochem J. 1985 Jul 1;229(1):141-51. doi: 10.1042/bj2290141.
An investigation into the measurement of Pi and ADP in rat liver in vivo and in freeze-clamped extracts by 31P-n.m.r. spectroscopy was carried out. The concentration of Pi estimated in vivo is less than 25% [1 mM (mumol/ml of cell water)] of the value obtained from freeze-clamped liver (4 mM), whereas ADP in vivo is undetectable (1.4 mM in vitro). At 5 min after infusion of 750 mg of fructose/kg, the Pi content of liver extracts fell to 1.3 mM, whereas Pi is undetectable in vivo under these conditions [Griffiths, Stevens, Gadian, Iles & Porteous (1980) Biochem. Soc. Trans. 8, 641]. The results indicate that the lower Pi and ADP concentrations found in vivo may be due to compartmentation or binding rather than to degradation of labile organic phosphates during extraction. The results are discussed with reference to previous measurements of liver phosphates and investigations of compartmentation in the liver, as are some of the possible consequences for metabolic control in the liver of low ADP and Pi concentrations.
采用³¹P-核磁共振波谱法对大鼠肝脏活体及冷冻钳夹提取物中无机磷酸（Pi）和二磷酸腺苷（ADP）的测量进行了研究。活体中估算的Pi浓度低于冷冻钳夹肝脏中测得值（4 mM）的25%[1 mM（每毫升细胞水所含微摩尔数）]，而活体中的ADP无法检测到（体外为1.4 mM）。静脉注射750 mg果糖/千克体重后5分钟，肝脏提取物中的Pi含量降至1.3 mM，而在此条件下活体中Pi无法检测到[格里菲思、史蒂文斯、加迪安、艾尔斯和波蒂厄斯（1980年）《生物化学学会会报》8, 641]。结果表明，活体中较低的Pi和ADP浓度可能是由于分隔或结合，而非提取过程中不稳定有机磷酸盐的降解。结合先前对肝脏磷酸盐的测量以及对肝脏分隔的研究，对这些结果进行了讨论，同时也探讨了低ADP和Pi浓度对肝脏代谢控制可能产生的一些影响。
