Intestinal absorption of cytidine diphosphate choline and its changes in the digestive tract.

Abstract

Intestinal absorption of cytidine diphosphate choline (CDP choline), its structural changes in the digestive tract, and hepatic uptake have been investigated in rats using 14C-labeled (14CH3 attached to N of choline) and 3H-labeled (at C5 of pyrimidine) compounds. The results indicate that: 1) CDP-choline is relatively stable in the stomach, but is quickly degraded into cytidine and choline in the intestine; 2) The hepatic uptakes of 14C and 3H reach the maximum in two to three hours after oral administration; 3) Whereas the amount of 14C remaining in the gut is inversely related to the hepatic uptake, no similar correlation is seen with 3H-labeled CDP-choline, and 4) Extrahepatic uptake of 14C and 3H is very small. The possibility of phosphorylation in the mucosa of choline and cytidine has been discussed, based on the differences in relative amount of radioactivity in individual broken-down products in the intestinal lumen and mucosa.It has been established that B vitamins exist in nature mostly in their coenzyme forms. Despite the general interest in the intestinal absorption of these vitamins and coenzyme forms subsequent to their recent clinical uses for therapeutic pur poses, our knowledge is very limited. Even the long dispute of whether vitamin Bl is absorbed after phosphorylation (1, 2), or passively without chemical changes (3), has not as yet been settled, although more recent data suggest active transport across the intestinal mucosa involving phosphorylation (4, 5).Coenzyme forms of B vitamins are relatively unstable in the gut. Flavine

Neuroprotective Properties of Citicoline: Facts, Doubts and Unresolved Issues

“…Yashima et al [65] used citicoline doubly-labelled with carbon-14 at the methyl groups of choline and tritium at C5 of pyrimidine, and obtained evidence of CDP-choline being broken down in the intestine, resulting in release of choline and cytidine, likely due to the actions of intestinal esterases and pyrophosphatases. However, the authors concluded that “these split compounds as well as the original CDP-choline may be absorbed from the intestinal mucosa as such”.…”

Changes in brain striatum dopamine and acetylcholine receptors induced by chronic CDP‐choline treatment of aging mice

“…Cytidine 5'-diphosphocholine (CDP-choline) has been widely used for the treatment of different diseases of the central nervous system (Manaka et al, 1974;Salvadorini et al, 1975;Cohadon et al, 1982;Lecuire & Duplay, 1982). Membrane diffusion of this compound, after intravenous or oral administration, requires splitting of the molecule into CMP and phosphocholine, which are later metabolized to cytidine and choline (Yashima et al, 1975;Lopez-G. Coviella et al, 1987). These two major circulating products are then incorporated into their respective cellular pools and their increased concentrations would account for the pharmacological properties of CDP-choline.…”

“…Membrane diffusion of this compound, after intravenous or oral administration, requires splitting of the molecule into CMP and phosphocholine, which are later metabolized to cytidine and choline (Yashima et al, 1975;Lopez-G. Coviella et al, 1987). These two major circulating products are then incorporated into their respective cellular pools and their increased concentrations would account for the pharmacological properties of CDP-choline.…”