Zs-Nagy I, Zs-Nagy V, Pieri C, Giuli C, Del Moro M
Gerontology. 1978;24(1):12-26. doi: 10.1159/000212232.
Phytohemagglutinin P (PHA-P) was administered in form of intralumbar injection to old (24-27 months) female Wistar rats. PHA-P has an inductive effect also on the nerve cells. The thermal denaturation characteristics of the DNA in situ as well as the numerical density of perichromatin granules being connected to the extranucleolar RNA synthesis returned practically to the young levels in the large brain cortical cells and in the cerebellar granular cells 20 h after the injection. The reversal of these aging phenomena was accompanied by a significant decrease of intranuclear and intracytoplasmic K+ content measured by X-ray microanalysis in the dry mass, whereas Na+ and Cl- remained unchanged. If PHA-P causes also some (1-2%) rehydration of the old neurons, the total ionic strength in the cell due to the monovalents may even reach the young level. The possible regulatory role of the ionic strength and the Na+/K+ ratio in the chromatin function is discussed on the basis of experimental data. It is the first time that the reversibility of some cytological aging parameters has been demonstrated in vivo.
将植物血凝素P（PHA-P）以腰椎内注射的形式给予老龄（24 - 27个月）雌性Wistar大鼠。PHA-P对神经细胞也有诱导作用。注射后20小时，大脑皮层细胞和小脑颗粒细胞中DNA的原位热变性特征以及与核仁外RNA合成相关的染色质周边颗粒的数量密度实际上恢复到了年轻水平。这些衰老现象的逆转伴随着通过X射线微分析在干物质中测量的核内和胞质内K⁺含量的显著降低，而Na⁺和Cl⁻保持不变。如果PHA-P也导致老龄神经元有一定程度（1 - 2%）的再水化，那么由于单价离子导致的细胞内总离子强度甚至可能达到年轻水平。基于实验数据讨论了离子强度和Na⁺/K⁺比值在染色质功能中可能的调节作用。这是首次在体内证明某些细胞学衰老参数的可逆性。
