Beaulieu C F, Clark J I
Department of Biological Structure, University of Washington School of Medicine, Seattle 98195.
Invest Ophthalmol Vis Sci. 1990 Jul;31(7):1339-47.
The authors studied the relationships between lens phosphate metabolites and transparency in (1) normal intact calf lenses, (2) whole-lens homogenates, (3) cortical homogenates, and (4) cortical homogenates that were opacified by the addition of calcium. Transparency was measured with the use of laser spectroscopy. Phosphate metabolites and pH were measured with the use of phosphorus nuclear magnetic resonance (31P NMR) spectroscopy. 31P NMR spectra of fresh whole-lens homogenates and fresh intact lenses were nearly identical. In fresh tissue, adenosine triphosphate (ATP) accounted for 59%, 55%, and 61% of the total phosphorus detected in intact lenses, whole-lens homogenates, and cortical homogenates, respectively. As ATP decreased over time to undetectable levels, no loss of transparency was measured, indicating no relationship between ATP levels and lens opacification. In contrast, the authors found that the loss of transparency in cortical homogenates produced by additions of 5, 10, and 20 mM calcium chloride was associated with increased levels of sugar phosphates and glycerol phosphorylcholine and with decreased levels of inorganic phosphate. Loss of cortical transparency was associated with both increases or decreases in pH from the normal value.
作者研究了晶状体磷酸盐代谢物与透明度之间的关系，研究对象包括：（1）正常完整的小牛晶状体；（2）全晶状体匀浆；（3）皮质匀浆；（4）添加钙后变混浊的皮质匀浆。使用激光光谱法测量透明度。使用磷核磁共振（31P NMR）光谱法测量磷酸盐代谢物和pH值。新鲜全晶状体匀浆和新鲜完整晶状体的31P NMR光谱几乎相同。在新鲜组织中，三磷酸腺苷（ATP）分别占完整晶状体、全晶状体匀浆和皮质匀浆中检测到的总磷的59%、55%和61%。随着ATP随时间下降至检测不到的水平，未检测到透明度的损失，这表明ATP水平与晶状体混浊之间没有关系。相反，作者发现，添加5、10和20 mM氯化钙导致皮质匀浆透明度丧失，这与糖磷酸盐和甘油磷酸胆碱水平升高以及无机磷酸盐水平降低有关。皮质透明度丧失与pH值相对于正常值的升高或降低均相关。
