Survey of osmolytes in renal cell lines.
Survey of osmolytes in renal cell lines.
复制标题
肾细胞系渗透调节剂的调查。
作者：
T. Nakanishi;R. Balaban;M. Burg
在抗利尿期间，肾髓质中的细胞外液由于高浓度的氯化钠和尿素而处于高渗状态。在这些条件下，细胞含有高浓度的有机渗透剂，即山梨醇、肌醇、甘油磷酸胆碱（GPC）和甜菜碱，以平衡细胞外的高渗透压。这些有机渗透剂可增加细胞渗透压，但不会扰乱细胞内环境，从而降低细胞大分子的功能。本研究调查了许多细胞系在高浓度氯化钠和/或尿素培养基中的生存能力以及有机渗透剂的积累。在测试的肾细胞系中，当含有较高浓度的肌醇、GPC 和甜菜碱时，MDCK、GRB-MAL1 和 A6 细胞在高渗介质中增殖，但髓质间质细胞 LLC-PK1 和 LLC-PK3 不增殖，非肾 HTC-BH 细胞、MDCK、LLC-PK1 和 LLC-PK3 细胞也不增殖。 在含有高 NaCl（含或不含高尿素）的培养基中培养，当在等渗培养基中生长时，这些渗透剂的水平要低得多或检测不到。在含有 NaCl 的高渗培养基中，GRB-MAL1 细胞中山梨醇和较小程度的肌醇升高，但在等渗培养基中则没有升高。当仅添加尿素以增加渗透压时，有机渗透压物质的积累较少。因此，与先前在肾髓质中发现的一样，一种或另一种细胞系在体外积累了相同的渗透剂。这些细胞系提供了研究渗透剂积累的模型。
In renal medullas during antidiuresis, the extracellular fluid is hyperosmotic because of high concentrations of NaCl and urea. Under those conditions, the cells contain high concentrations of organic osmolytes, namely sorbitol, myo-inositol, glycerophosphorylcholine (GPC), and betaine to balance the extracellular hyperosmolality. These organic osmolytes increase cell osmolality without perturbing the intracellular milieu in ways that would degrade the function of cellular macromolecules. The present study surveyed a number of cell lines for the ability to survive in media with high concentrations of NaCl and/or urea and for the accumulation of organic osmolytes. Of the renal cell lines tested, MDCK, GRB-MAL1, and A6 cells proliferated in hyperosmotic media, but medullary interstitial cells LLC-PK1 and LLC-PK3 did not proliferate, nor did nonrenal HTC-BH cells, MDCK, LLC-PK1, and LLC-PK3 cells contained higher concentrations of myo-inositol, GPC, and betaine when cultured in media containing high NaCl (with or without high urea) and much lower or undetectable levels of these osmolytes when grown in isosmotic media. Sorbitol, and to a lesser extent myo-inositol, were elevated in GRB-MAL1 cells in media hyperosmotic with NaCl but not in isosmotic media. There was less accumulation of organic osmolytes when only urea was added to increase osmolality. Thus the same osmolytes were accumulated by one or another cell line in vitro as were previously found in renal medullas. These cell lines provide models for studying osmolyte accumulation.