Ginès P, Jiménez W
Liver Unit, Hospital Clínic i Provincial, Barcelona, Catalunya, Spain.
J Hepatol. 1996 Apr;24(4):506-12. doi: 10.1016/s0168-8278(96)80174-7.
An impairment in the renal capacity to excrete water is a common finding in patients with cirrhosis and ascites. In some patients this abnormality is minor since it is only detectable by measuring urine volume or free water clearance after a water load and is not associated with changes in plasma osmolality and serum sodium concentration. In other patients the intensity of the disorder is such that they are not able to eliminate their regular water intake, and develop dilutional hyponatremia and hypoosmolality. The renal capacity to excrete water is one of the most useful prognostic indicators in patients with cirrhosis and ascites. The main pathogenic factors of the impaired water excretion in human cirrhosis are an increased plasma concentration of AVP, a reduced renal synthesis of prostaglandins and a reduced delivery of filtrate to the ascending limb of the loop of Henle. At present, no effective therapy exists for the management of this complication. Two types of drugs have recently been reported that selectively increase renal water excretion, antagonists of the AVP V2 receptors and kappa-opioid agonists. Experimental studies have shown that both substances improve water excretion in rats with cirrhosis and ascites. Therefore, these drugs may represent a novel therapeutic tool in the management of spontaneous hyponatremia in cirrhosis and in the treatment or prevention of diuretic-induced hyponatremia in these patients.
肝硬化和腹水患者中，肾脏排水能力受损是常见现象。在一些患者中，这种异常较轻微，因为只有通过测量水负荷后的尿量或自由水清除率才能检测到，且与血浆渗透压和血清钠浓度的变化无关。在其他患者中，这种紊乱的程度使得他们无法排出正常摄入的水分，从而出现稀释性低钠血症和低渗状态。肾脏排水能力是肝硬化和腹水患者最有用的预后指标之一。人类肝硬化患者排水受损的主要致病因素是抗利尿激素（AVP）血浆浓度升高、肾脏前列腺素合成减少以及滤过液输送至髓袢升支减少。目前，对于这种并发症尚无有效的治疗方法。最近报道了两类能选择性增加肾脏排水的药物，即AVP V2受体拮抗剂和κ-阿片受体激动剂。实验研究表明，这两种物质均可改善肝硬化和腹水大鼠的排水情况。因此，这些药物可能是治疗肝硬化患者自发性低钠血症以及治疗或预防这些患者利尿剂诱发低钠血症的新型治疗手段。
