Stokes G S, Norris L A, Marwood J F, Johnston H, Caterson R J
Department of Clinical Pharmacology, Royal North Shore Hospital, St. Leonards, New South Wales, Australia.
Nephron. 1990;54(2):127-33. doi: 10.1159/000185832.
Deproteinized plasma from patients with renal failure had an inhibitory effect on Na,K ATPase activity measured in vitro by a linked-enzyme assay. No inhibitory effect was observed with plasma from normal subjects or from patients undergoing chronic ambulatory peritoneal dialysis. The inhibition of Na,K ATPase whether measured by the linked-enzyme assay or by 86Rb uptake in guinea pig aortic strips was decreased acutely by a single hemodialysis treatment, but was unaffected during a time-control study or ultrafiltration. Changes in Na,K ATPase activity and in Rb uptake were correlated, indicating that the presence of the enzyme inhibitor in uremic plasma was associated with depressed Na pump activity. Change in inhibition of Na,K ATPase activity did not correlate with change in body weight. Dialysis in vitro against a membrane of molecular weight 3,500 cut-off decreased the inhibitory effect of uremic plasma on Na,K ATPase. It was concluded that a dialyzable, low-molecular-weight Na,K ATPase inhibitor circulates in uremia but has no demonstrable role in volume homeostasis.
通过连接酶测定法在体外测量，肾衰竭患者的脱蛋白血浆对钠钾ATP酶活性有抑制作用。正常受试者或接受持续性非卧床腹膜透析患者的血浆未观察到抑制作用。无论是通过连接酶测定法还是通过豚鼠主动脉条带对86Rb的摄取来测量，单次血液透析治疗可使钠钾ATP酶的抑制作用急性降低，但在时间对照研究或超滤过程中无影响。钠钾ATP酶活性和铷摄取的变化相关，表明尿毒症血浆中酶抑制剂的存在与钠泵活性降低有关。钠钾ATP酶活性抑制的变化与体重变化无关。用截留分子量为3500的膜进行体外透析可降低尿毒症血浆对钠钾ATP酶的抑制作用。得出的结论是，一种可透析的低分子量钠钾ATP酶抑制剂在尿毒症中循环，但在容量稳态中无明显作用。
