Racay P, Matejovicová M, Drgová A, Dobrota D, Kaplán P, Lehotský J, Mézesová V
Ustav lekárskej biochémie Jeseniovej lekárskej fakulty Univerzity Komenského v Martine.
Bratisl Lek Listy. 1998 Jul;99(7):386-94.
Interruption of cerebral blood flow leads to dissipation of ionic gradients as the consequence of ionic channel overstimulation and ionic pump failure. The aim of this work was to study the possible effects of ischaemia and ischaemia followed by reperfusion on biochemical properties of endoplasmic calcium pump and synaptosomal sodium pump and sodium/calcium exchanger. The results presented in this study showed that 15 minute ischaemia led to the inhibition of all three ionic transport systems, however in different degrees. 60 minute reperfusion following 15 minute ischaemia led to partial recovery of calcium pump and sodium/calcium exchanger. The activity of sodium pump was still significantly depressed. Ischaemia and ischemia followed by reperfusion did not affect kinetic parameters of calcium pump. On the other side, both ischaemia and ischaemia-reperfusion led to an increase of sodium pump affinity to ATP and a decrease of the enzyme affinity to potassium. The possible causes of the changes, as the alteration of membrane structure or altered enzymes phosphorylation are discussed in the study. In addition to the inhibitory effect of ischaemia-reperfusion injury, intracellular water accumulation, as the possible consequence of altered ion homeostasis, is documented by nuclear magnetic resonance (imaging).
脑血流中断会导致离子梯度消散，这是离子通道过度刺激和离子泵功能衰竭的结果。这项工作的目的是研究缺血以及缺血后再灌注对内质网钙泵、突触体钠泵和钠/钙交换器生化特性的可能影响。本研究给出的结果表明，15分钟的缺血导致所有三种离子转运系统受到抑制，不过程度有所不同。15分钟缺血后再灌注60分钟导致钙泵和钠/钙交换器部分恢复。钠泵的活性仍显著降低。缺血以及缺血后再灌注不影响钙泵的动力学参数。另一方面，缺血和缺血-再灌注均导致钠泵对ATP的亲和力增加，而该酶对钾的亲和力降低。研究中讨论了这些变化的可能原因，如膜结构改变或酶磷酸化改变。除了缺血-再灌注损伤的抑制作用外，核磁共振成像记录了作为离子稳态改变可能后果的细胞内水积聚。
