Does Aging Affect the Intestinal Transport of 5-Methyltetrahydrofolate?

Publisher Website
Google Scholar
Abstract
Aging is associated with increased incidence of folate deficiency. The mechanism responsible for the deficiency is not known but could include a decrease in the intestinal absorptive capacity for folates. Therefore, the intestinal absorptive capacity for folate in young and old rats was examined. The absorption of the natural folate derivative 5-methyltetrahydrofolate was assayed in 3 and 25 mo. old rats using jejunal everted sacs. The kinetic parameters of 5-methyltetrahydrofolate absorption disclosed apparent Kt [transport constant] of 7.7 and 6.54 .mu.M and Vmax of 0.96 and 1.14 nmol/g initial tissue wet wt per 30 min in young and old rats, respectively. An aging-associated decrease in the intestinal transport capacity for 5-methyltetrahydrofolate was not demonstrated. Therefore, the deficiency of folate found in the elderly is unlikely to be due to intestinal malabsorption of folate monoglutamates. Other mechanisms must play a role in the deficiency of folate seen in the elderly.