Oral cytidine 5'-diphosphate choline administration to rats increases brain phospholipid levels.

Exogenous cytidine 5'diphosphocholine (CDP-choline) is completely metabolized to circulating cytidine and choline. Both compounds enter the brain and can be used in phosphatidylcholine (PC) synthesis via the Kennedy (CDP-choline) cycle. We administered oral CDP-choline to 12 month-old rats (500 mg/kg/day) for 21, 42, or 90 days to determine whether this treatment would alter brain levels of PC and the other structural phospholipids, phosphatidylserine (PS) and phosphatidylethanolamine (PE). After 42 days, brain PC levels increased significantly (p < 0.01) by 23.3%; after 90 days PC increased by 30% (p < 0.01), PS by 37.2% (p < 0.01), and PE by 13% (not significant). The ratios of each of the phospholipids to total membrane phospholipids were unchanged. These data demonstrate that repeated oral CDP-choline administration can increase the amounts of phospholipids in brain membranes, thus providing a rationale for using this compound in brain diseases that damage neurons.