Effects of cataractogenesis on the CDP-choline pathway: Increased phospholipid synthesis in lenses from galactosemic rats and 13/N guinea pigs

We investigated the effects of cataractogenesis on phospholipid (P-lipid) synthesis in sugar cataracts from galactosemic rats and in hereditary cataracts from 13/N guinea pigs. Cataractous lenses from rats fed a 50% galactose diet for 7 days were incubated 24 h with radiolabeled choline or ethanolamine and the P-lipids were extracted. The galactosemic cataracts synthesized twice as much phosphatidylcholine (PtdCho) as control rat lenses, and Phosphatidylethanolamine synthesis also was increased. Similar analysis of cataractous lenses from 3-week-old 13/N guinea pigs showed a 3-fold increase in PtdCho synthesis compared with control lenses. In all cases, the P-lipid precursor pool was lower in cataracts than in control lenses. The increased P-lipid synthesis in these cataracts may represent a membrane repair response to cataractogenic stress.