Winkler B S, Riley M V
Eye Research Institute, Oakland University, Rochester, Michigan 48309.
Invest Ophthalmol Vis Sci. 1991 Aug;32(9):2593-8.
The adenosine triphosphate (ATP) content was measured independently in separated capsule-epithelium and fibers from whole rabbit lenses, both fresh and after incubation under various combinations of glucose and oxygen deprivation. Lactate production was also measured during aerobic and anaerobic incubations of whole lenses and of monolayers of cultured epithelial cells. The fresh capsule-epithelium contained 3.3 nmoles ATP, whereas the decapsulated lens contained 410 nmoles ATP, a value that was indistinguishable from that of the whole, intact lens. In the presence of glucose, the fibers and epithelium each maintained their respective ATP content under aerobic and anaerobic conditions. In the absence of glucose, the ATP content in each fraction declined with time, but only in the epithelium was the rate of decline of ATP significantly faster in nitrogen than in oxygen. In whole lens, the rates of anaerobic and aerobic lactate production were similar, whereas in the cultured epithelial monolayers, the anaerobic rate was two-fold greater than in oxygen. From this it is concluded that approximately 50% of the ATP of the epithelial cells is derived from oxidative metabolism. A Pasteur response shown here for the first time with the cultured epithelium allows these cells to compensate for the loss of ATP production when mitochondrial oxidation is curtailed. The epithelium does not contribute to the ATP content of the lens fibers under aerobic or anaerobic conditions.
分别测定了新鲜的以及在葡萄糖和缺氧的不同组合下孵育后的完整兔晶状体中分离出的囊膜 - 上皮细胞和纤维中的三磷酸腺苷（ATP）含量。还测定了完整晶状体以及培养的上皮细胞单层在需氧和厌氧孵育期间的乳酸生成量。新鲜的囊膜 - 上皮细胞含有3.3纳摩尔ATP，而去囊膜的晶状体含有410纳摩尔ATP，该值与完整的整个晶状体的值无明显差异。在有葡萄糖存在的情况下，纤维和上皮细胞在需氧和厌氧条件下均保持各自的ATP含量。在没有葡萄糖的情况下，每个组分中的ATP含量随时间下降，但仅上皮细胞中ATP的下降速率在氮气中比在氧气中明显更快。在完整晶状体中，厌氧和需氧乳酸生成速率相似，而在培养的上皮细胞单层中，厌氧速率比在氧气中高两倍。由此得出结论，上皮细胞约50%的ATP来自氧化代谢。首次在培养的上皮细胞中显示出的巴斯德效应使这些细胞能够在线粒体氧化减少时补偿ATP生成的损失。在需氧或厌氧条件下，上皮细胞对晶状体纤维的ATP含量没有贡献。
