Jernigan H M, Zigler J S
Department of Biochemistry, University of Tennessee, Memphis 38163.
Exp Eye Res. 1989 Nov;49(5):901-9. doi: 10.1016/s0014-4835(89)80048-x.
Phosphorylcholine (P-choline) and phosphorylethanolamine (P-ethanolamine) are important precursors of phospholipids. The metabolism and concentration of P-choline has been shown to change in animal models of cataract, especially in oxidatively or osmotically stressed rat lenses. The concentrations of P-choline and P-ethanolamine were determined in monkey lenses and in normal and cataractous human lenses, and the rate of synthesis of P-choline was determined in human and monkey lenses. The concentration of P-choline in 53 clear human lenses was 0.94 mM (+/- 0.31 S.D.) and was relatively unaffected by age, eye bank storage, or freezing. There was a 70% decrease in P-choline in brown cataracts but no significant change from normal in non-brown cataracts. The concentration of P-ethanolamine in human lenses was 0.45 mM (+/- 0.26 S.D.), and it appeared to decrease during frozen storage of lenses and in cataracts. The concentrations of P-choline and P-ethanolamine in 12 rhesus monkey lenses were 1.51 mM (+/- 0.27 S.D.) and 0.75 mM (+/- 0.14 S.D.), respectively. The rate of synthesis of P-choline in monkey lenses incubated with [3H]choline was 8 nmol hr-1 g-1 wet weight in 1 mM choline. Adult human lenses incubated in 1 mM choline synthesized P-choline at a rate of 23 nmol hr-1 g-1 (+/- 6 S.D.). This limited capacity for P-choline synthesis in primate lenses may contribute to the lower P-choline concentration relative to rat lenses, which contain 11 mM P-choline and can synthesize P-choline at an apparent maximum rate of 130 nmol hr-1 g-1.
磷酰胆碱（P - 胆碱）和磷酰乙醇胺（P - 乙醇胺）是磷脂的重要前体。在白内障动物模型中，尤其是在氧化或渗透压应激的大鼠晶状体中，P - 胆碱的代谢和浓度已被证明会发生变化。测定了猴晶状体以及正常和白内障患者晶状体中P - 胆碱和P - 乙醇胺的浓度，并测定了人和猴晶状体中P - 胆碱的合成速率。53个透明人晶状体中P - 胆碱的浓度为0.94 mM（±0.31标准差），相对不受年龄、眼库储存或冷冻的影响。棕色白内障中P - 胆碱减少了70%，但非棕色白内障与正常相比无显著变化。人晶状体中P - 乙醇胺的浓度为0.45 mM（±0.26标准差），在晶状体冷冻储存期间和白内障中似乎会降低。12个恒河猴晶状体中P - 胆碱和P - 乙醇胺的浓度分别为1.51 mM（±0.27标准差）和0.75 mM（±0.14标准差）。在含有[³H]胆碱的培养基中孵育的猴晶状体，在1 mM胆碱存在下，P - 胆碱的合成速率为8 nmol·hr⁻¹·g⁻¹湿重。在1 mM胆碱中孵育的成人晶状体合成P - 胆碱的速率为23 nmol·hr⁻¹·g⁻¹（±6标准差）。灵长类动物晶状体中P - 胆碱合成能力有限，这可能导致其P - 胆碱浓度低于大鼠晶状体，大鼠晶状体含有11 mM P - 胆碱，其P - 胆碱合成的表观最大速率可达130 nmol·hr⁻¹·g⁻¹。
