Rybak S L, Murphy R F
Department of Biological Sciences and Center for Light Microscope Imaging and Biotechnology, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
J Cell Physiol. 1998 Jul;176(1):216-22. doi: 10.1002/(SICI)1097-4652(199807)176:1<216::AID-JCP23>3.0.CO;2-3.
Endosomal and lysosomal pH values have been determined for many established cultured cell lines of different origins. These cell lines may be grouped into two classes based on observed differences in pH of early (recycling) endosomes. Members of the first class typically have an early endosomal pH of 6.2, whereas members of the second class typically have an early endosomal pH of 5.4. Because established cell lines may have developed artificial differences in endosomal pH due to extended culture, it remains to be determined if endosomal pH differences exist in vivo and whether they are functionally significant. To address this question, we generated adherent primary explants from mouse kidney (primarily epithelial cells) and heart (primarily fibroblasts and cardiac muscle cells). Interestingly, enhanced acidification was observed in heart cell endosomes (pH = 5.5) compared with kidney cell endosomes (pH = 6.0). These results indicate that differences in endosomal pH do not solely arise from extended cell culture and imply that such differences may be important for the proper functioning of different cell types.
已经测定了许多源自不同组织的成熟培养细胞系的内体和溶酶体pH值。根据早期（循环）内体pH值的观察差异，这些细胞系可分为两类。第一类成员的早期内体pH值通常为6.2，而第二类成员的早期内体pH值通常为5.4。由于长期培养，成熟细胞系可能在内体pH值上产生人为差异，因此体内是否存在内体pH差异以及它们是否具有功能意义仍有待确定。为了解决这个问题，我们从小鼠肾脏（主要是上皮细胞）和心脏（主要是成纤维细胞和心肌细胞）中生成了贴壁原代外植体。有趣的是，与肾细胞内体（pH = 6.0）相比，在心脏细胞内体中观察到酸化增强（pH = 5.5）。这些结果表明，内体pH差异并非仅由长期细胞培养引起，这意味着这种差异可能对不同细胞类型的正常功能很重要。
