Lorenz B, Münkner J, Oliveira M P, Kuusksalu A, Leitão J M, Müller W E, Schröder H C
Institut für Physiologische Chemie, Abteilung Angewandte Molekularbiologie, Universität, Mainz, Germany.
Biochim Biophys Acta. 1997 Apr 17;1335(1-2):51-60. doi: 10.1016/s0304-4165(96)00121-3.
Age-dependent studies show that the amount of inorganic polyphosphate in rat brain strongly increases after birth. Maximal levels were found in 12-months old animals. Thereafter, the concentration of total polyphosphate decreases to about 50%. This decrease in the concentration of total polyphosphate is due to a decrease in the amount of insoluble, long-chain polyphosphates. The amount of soluble, long-chain polyphosphates does not change significantly in the course of ageing. In rat embryos and newborns, mainly soluble polyphosphates could be detected. In rat liver, the age-dependent changes are less pronounced. The changes in polyphosphate level are accompanied by changes in exopolyphosphatase activity, which degrades the polymers to orthophosphate; highest enzyme activities were found when the polyphosphate level was low. Induction of apoptosis in the human leukemic cell line HL-60 by actinomycin D results in degradation of long polyphosphate chains. The total polyphosphate content does not change significantly in apoptotic cells.
年龄依赖性研究表明，大鼠大脑中无机多聚磷酸盐的含量在出生后会大幅增加。在12个月大的动物中发现了最高水平。此后，总多聚磷酸盐的浓度降至约50%。总多聚磷酸盐浓度的这种下降是由于不溶性长链多聚磷酸盐的量减少。可溶性长链多聚磷酸盐的量在衰老过程中没有显著变化。在大鼠胚胎和新生儿中，主要可检测到可溶性多聚磷酸盐。在大鼠肝脏中，年龄依赖性变化不太明显。多聚磷酸盐水平的变化伴随着外切多聚磷酸酶活性的变化，该酶将聚合物降解为正磷酸盐；当多聚磷酸盐水平较低时发现了最高的酶活性。放线菌素D诱导人白血病细胞系HL-60凋亡会导致长多聚磷酸盐链的降解。凋亡细胞中的总多聚磷酸盐含量没有显著变化。
