Effct of hemodialysis on brain metabolism

在10只体重约2kg的尿毒症家兔上研究了血液透析对脑组织细胞内pH值的影响。通过右肾切除术和左肾大部切除术诱导尿毒症。使用小型中空纤维装置和碳酸氢盐透析液进行透析。通过使用31 P核磁共振光谱法，使用JEOL FX-200 NMR光谱仪（JOEL，Tokyo），在80.75MHz下操作31 P-NMR，监测pH变化。每个光谱通过累积600个脉冲获得，脉冲延迟为4.8微秒。和大约0.5秒的采集时间。发现血液流速在200 ml/hr和414 ml/hr之间的180分钟透析可降低血浆尿素和肌酐浓度。而前顶叶脑内高能磷酸盐ATP、磷酸单酯、磷酸二酯、无机磷酸盐的相对浓度及pH值无明显变化。本实验中尿毒症的程度和透析的有效性可能不足以诱导脑水和电解质代谢的改变。MRS是研究不同透析方法对活体脑pH值和能量代谢影响的有力新工具。

The effect of hemodialysis on intracellular pH in brain tissue was studied in ten uremic hares weighing about 2 kg. Uremia was induced by right nephrectomy and left subtotal nephrectomy. Dialysis was done with a small-sized hollow fiber unit and bicarbonate dialysate. The pH changes was monitored by use of 31 P nuclear magnetic resonance spectroscopy, using JEOL FX-200 NMR spectrometer (JOEL, Tokyo), operating at 80.75 MHz for 31 P-NMR. Each Spectrum was acquired by accumulation of 600 pulses with a pulse delay of 4.8 microsec. and acquisition time of about 0.5 seconds. Dialysis of 180 minutes with a blood flow rate between 200 ml/hr and 414 ml/hr was found to lower plasma urea and creatinine concentrations. However, no significant changes of the relative concentrations of the energy rich phosphates ATP, phosphomonoester, phosphodiester, inorganic phosphate and the pH were found in the front parietal brain. There was a possibility that the extent of uremia and the efficacy of dialysis in this experiment was insufficient to induce brain water and electrolyte metabolism alterations. MRS was a powerful new tool for studying effects of various methods of dialysis on brain pH and energy metabolism in vivo.