Johnson J P, Steele R E, Perkins F M, Wade J B, Preston A S, Green S W, Handler J S
Am J Physiol. 1981 Aug;241(2):F129-38. doi: 10.1152/ajprenal.1981.241.2.F129.
Two continuous cell lines (TB-M and TB-6c) derived from epithelial cells of the toad urinary bladder form epithelia in culture that manifest hormone-sensitive transepithelial transport. Development of transepithelial electrical resistance (R) and transport rate (ISC) are dependent on time and density of cells seeded, but steady-state ISC and R are characteristic for each cell line and independent of seeding density. Some responses of intact toad bladder are preserved in culture, whereas others are altered or absent. Neither cell line responds to vasopressin. Analogues of cAMP increase sodium transport and urea permeability in both cell lines but do not affect water permeability. The intramembrane particle aggregates associated with the vasopressin- and cAMP-induced increase in water permeability of the intact bladder could not be detected in the cell lines. Aldosterone increases sodium transport in both cell lines, and the time course and concentration dependence of the response to aldosterone are similar to those of the intact bladder. The relative effect of a series of steroids on ISC reveals corticosterone to be a more potent mineralocorticoid in cultured cells than in the intact bladder.
从蟾蜍膀胱上皮细胞衍生而来的两种连续细胞系（TB - M和TB - 6c）在培养中形成上皮，表现出激素敏感性跨上皮转运。跨上皮电阻（R）和转运速率（ISC）的发展取决于接种细胞的时间和密度，但稳态ISC和R对每个细胞系而言是特征性的，且与接种密度无关。完整蟾蜍膀胱的一些反应在培养中得以保留，而其他反应则发生改变或缺失。两种细胞系均对加压素无反应。cAMP类似物可增加两种细胞系中的钠转运和尿素通透性，但不影响水通透性。在细胞系中未检测到与加压素和cAMP诱导的完整膀胱水通透性增加相关的膜内颗粒聚集。醛固酮可增加两种细胞系中的钠转运，且对醛固酮反应的时间进程和浓度依赖性与完整膀胱相似。一系列类固醇对ISC的相对作用表明，皮质酮在培养细胞中是比在完整膀胱中更有效的盐皮质激素。
