Avner E D, Sweeney W E, Finegold D N, Piesco N P, Ellis D
Kidney Int. 1985 Sep;28(3):447-55. doi: 10.1038/ki.1985.151.
To study the possible role of altered transtubular transport in renal tubular cyst formation, the ontogeny of renal Na-K ATPase was studied during glucocorticoid-induced cystic metanephric tubular development in serum-free, murine organ culture (SFMOC). Utilizing an enzyme-linked kinetic microassay, a developmental profile of total ATPase and specific Na-K ATPase activity was established for control (CON) and glucocorticoid-induced cystic organ culture (CY) explants. During 120 hr of CON and CY organ culture nephrogenesis total Na-K ATPase activity, specific Na-K ATPase activity, and the Na-K ATPase: total ATPase ratio progressively increased, simulating normal in vivo murine enzyme development. However, from 48 to 120 hr of organ culture, CY showed significant increases in Na-K ATPase activity when compared to CON at similar stages of development. Na-K ATPase activity (expressed as nmoles . min-1 . mg protein -1, mean +/- SD) was, at: 48 hr, CY 13.1 +/- 0.7 vs. CON 11.0 +/- 0.9 (P less than 0.01); 72 hr, CY 16.4 +/- 1.1 vs. CON 12.2 +/- 0.7 (P less than 0.001); 96 hr, CY 35.4 +/- 4.9 vs. CON 13.7 +/- 0.4 (P less than 0.001); and 120 hr, CY 26.1 +/- 1.4 vs. CON 16.3 +/- 0.9 (P less than 0.001). The initial differences in CY enzyme activity preceded the earliest ultrastructural evidence of cyst formation by 18 to 24 hr, while subsequent increases in Na-K ATPase activity in CY paralleled progressive tubular cyst formation. Tubular cyst formation in CY could be largely prevented by daily incubation of explants with ouabain, 0.2 mM (final concentration) X 120 min, without deleterious effects on overall metanephric development.(ABSTRACT TRUNCATED AT 250 WORDS)
为研究跨肾小管转运改变在肾小管囊肿形成中的可能作用，在无血清小鼠器官培养（SFMOC）中，对糖皮质激素诱导的囊性后肾肾小管发育过程中肾钠钾ATP酶的个体发生进行了研究。利用酶联动力学微量测定法，建立了对照（CON）和糖皮质激素诱导的囊性器官培养（CY）外植体中总ATP酶和特异性钠钾ATP酶活性的发育图谱。在CON和CY器官培养肾发生的120小时内，总钠钾ATP酶活性、特异性钠钾ATP酶活性以及钠钾ATP酶与总ATP酶的比值逐渐增加，模拟了正常的体内小鼠酶发育过程。然而，在器官培养的48至120小时内，与处于相似发育阶段的CON相比，CY的钠钾ATP酶活性显著增加。钠钾ATP酶活性（以纳摩尔·分钟⁻¹·毫克蛋白质⁻¹表示，平均值±标准差）在：48小时时，CY为13.1±0.7，CON为11.0±0.9（P＜0.01）；72小时时，CY为16.4±1.1，CON为12.2±0.7（P＜0.001）；96小时时，CY为35.4±4.9，CON为13.7±0.4（P＜0.001）；120小时时，CY为26.1±1.4，CON为16.3±0.9（P＜0.001）。CY酶活性的最初差异比最早的囊肿形成超微结构证据早18至24小时，而CY中钠钾ATP酶活性的随后增加与肾小管囊肿的逐渐形成平行。通过每天用0.2 mM（终浓度）的哇巴因孵育外植体120分钟，CY中的肾小管囊肿形成在很大程度上可以被阻止，且对整体后肾发育没有有害影响。（摘要截断于250字）
