Sechi L A, Melis A, Faedda R, Tedde R, Bartoli E
Institute of Clinica Medica Generale, University of Sassari, Italy.
Panminerva Med. 1992 Apr-Jun;34(2):85-92.
The basic tubular alteration present in Bartter's syndrome is still a subject of controversy. The possibility that a generalized defect in transmembrane ion transport underlies the disease has been extensively investigated. Previous evaluations of cellular sodium metabolism in Bartter's patients showed extremely variable findings. In the present study we have examined in red blood cells of two patients with Bartter's syndrome the intracellular Na+ and K+ concentrations, the activity of ouabain-sensitive Na+/K+ pump, furosemide sensitive Na+/K+ cotransport, Na+/Li+ countertransport, and the rate constant of Na+ and K+ passive permeability. We have compared these values with those of a control group. Ouabain-sensitive Na+/K+ pump activity was decreased in both patients, whereas Na+/Li+ countertransport was activated. One of the patients also exhibited markedly decreased intraerythrocyte K+ concentration and decreased furosemide-sensitive Na+/K+ cotransport. The other had increased Na+/K+ cotransport activity and Na+ passive permeability. Intracellular Na+ and passive permeability to K+ were normal in both subjects. Our results are partially consistent with previously reported observations, and indicate the existence of heterogeneous alterations of erythrocyte sodium transport systems in patients with Bartter's syndrome. Although some of these alterations could be secondary to the electrolyte metabolism derangements of this disease, others might be genetically transmitted and could cause the different renal tubular defects shown in Bartter's disease so far.
巴特综合征中存在的基本肾小管改变仍是一个有争议的话题。跨膜离子转运普遍缺陷是该疾病基础的可能性已得到广泛研究。以往对巴特综合征患者细胞钠代谢的评估结果差异极大。在本研究中，我们检测了两名巴特综合征患者红细胞内的Na⁺和K⁺浓度、哇巴因敏感的Na⁺/K⁺泵活性、呋塞米敏感的Na⁺/K⁺协同转运、Na⁺/Li⁺逆向转运以及Na⁺和K⁺被动通透性的速率常数。我们将这些值与对照组的值进行了比较。两名患者的哇巴因敏感的Na⁺/K⁺泵活性均降低，而Na⁺/Li⁺逆向转运被激活。其中一名患者还表现出红细胞内K⁺浓度显著降低以及呋塞米敏感的Na⁺/K⁺协同转运减少。另一名患者的Na⁺/K⁺协同转运活性和Na⁺被动通透性增加。两名受试者的细胞内Na⁺和对K⁺的被动通透性均正常。我们的结果部分与先前报道的观察结果一致，并表明巴特综合征患者红细胞钠转运系统存在异质性改变。虽然其中一些改变可能继发于该疾病的电解质代谢紊乱，但其他改变可能是遗传传递的，并且可能导致迄今为止巴特病中显示的不同肾小管缺陷。
