Intestinal absorption of beta-alanine, anserine and carnosine in rats

Absorption beta-alanine, anserine or carnosine from rat intestine was studied in vivo by a force feeding method and in vitro using an everted sac method. Possibility of anserine and carnosine hydrolysis prior to intestinal absorption was also investigated using a glycylleucine dipeptidase-containing fraction prepared from rat intestine. The following results were obtained. 1) Anserine and carnosine were absorbed as they were from rat small intestine. 2) Both anserine and carnosine were partially hydrolyzed in vitro by the glycylleucine dipeptidase-containing fraction. Carnosine was hydrolyzed faster than anserine. The above rather conflicting results suggest that physiological amounts of anserine and carnosine might be absorbed from rat small intestine in dipeptide forms.