CYCLO-(LL-DIMETHIONINE) IS NOT UTILIZED BY RATS AS A METHIONINE SOURCE

A low casein diet supplemented with 0.2-0.3% L-methionine promotes gro wth in rats, although it causes liver fat accumulation. Oligo-L-methio nine on the other hand, prepared by papain-catalyzed oligomerization o f L-methionine ethylester, stimulates growth in rats without causing l iver fat accumulation, when added to a 8% casein diet. Oligo-L-methion ine is a mixture of oligomers, with a oligomerization degree of 5 to 1 2, and is hydrolyzed very slowly by pancreatic juice and everted gut r ings of rats. A methionine derivative, cycle (LL-dimethionine), was ex amined in this study as it is hydrolyzed and/or absorbed very slowly f rom the intestinal tract and it was expected to be utilized as a methi onine source without causing liver fat accumulation, when added to a l ow casein diet. It consists of two methionine residues linked together by two cis-peptide bonds and, therefore, is expected to be hydrolyzed and/or absorbed very slowly from intestinal tract. However, although cycle (LL-dimethionine) was absorbed slowly from the intestinal tract, it was not utilized by rats as a methionine source, when added to 8% casein.