Flögel U, Niendorf T, Serkowa N, Brand A, Henke J, Leibfritz D
Institut für Organische Chemie, Universität Bremen, Germany.
Neurochem Res. 1995 Jul;20(7):793-802. doi: 10.1007/BF00969691.
Diffusion-weighted in vivo 1H-NMR spectroscopy of F98 glioma cells embedded in basement membrane gel threads showed that the initial cell swelling to about 180% of the original volume induced under hypotonic stress was followed by a regulatory volume decrease to nearly 100% of the control volume in Dulbecco's modified Eagle's medium (DMEM) but only to 130% in Krebs-Henseleit buffer (KHB, containing only glucose as a substrate) after 7 h. The initial cell shrinkage to approx. 70% induced by the hypertonic stress was compensated by a regulatory volume increase which after 7 h reached almost 100% of the control value in KHB and 75% in DMEM. 1H-, 13C- and 31P-NMR spectroscopy of perchloric acid extracts showed that these volume regulatory processes were accompanied by pronounced changes in the content of organic osmolytes. Adaptation of intra- to extracellular osmolarity was preferentially mediated by a decrease in the cytosolic taurine level under hypotonic stress and by an intracellular accumulation of amino acids under hypertonic stress. If these solutes were not available in sufficient quantities (as in KHB), the osmolarity of the cytosol was increasingly modified by biosynthesis of products and intermediates of essential metabolic pathways, such as alanine, glutamate and glycerophosphocholine in addition to ethanolamine. The cellular nucleoside triphosphate level measured by in vivo 31P-NMR spectroscopy indicated that the energy state of the cells was more easily sustained under hypotonic than hypertonic conditions.
对包埋于基底膜凝胶丝中的F98胶质瘤细胞进行体内扩散加权1H-NMR光谱分析，结果显示，在低渗应激下，细胞最初肿胀至原始体积的约180%，随后在杜氏改良伊格尔培养基（DMEM）中调节性体积减小至对照体积的近100%，但在克雷布斯-亨泽莱特缓冲液（KHB，仅含葡萄糖作为底物）中7小时后仅减小至130%。高渗应激诱导细胞最初收缩至约70%，随后通过调节性体积增加得到补偿，7小时后，在KHB中几乎达到对照值的100%，在DMEM中达到75%。高氯酸提取物的1H-、13C-和31P-NMR光谱分析表明，这些体积调节过程伴随着有机渗透溶质含量的显著变化。低渗应激下，细胞内渗透压与细胞外渗透压的适应主要通过胞质牛磺酸水平降低介导，高渗应激下则通过氨基酸在细胞内积累介导。如果这些溶质数量不足（如在KHB中），除乙醇胺外，必需代谢途径的产物和中间体（如丙氨酸、谷氨酸和甘油磷酸胆碱）的生物合成会越来越多地改变胞质渗透压。通过体内31P-NMR光谱测量的细胞核苷三磷酸水平表明，低渗条件下细胞的能量状态比高渗条件下更容易维持。
