Utilization of L-Methionine Sulfoxide by the Rat

Abstract

Methionine sulfoxide is an expected oxidation product of methionine in foods which undergo lipid oxidation or are treated with strong oxidizing agents like hydrogen peroxide. The extent to which methionine sulfoxide could replace methionine in the diet has therefore been tested using diets which are based upon mixtures of synthetic amino acids. This technique allows the exclusive and controlled testing of methionine sulfoxide, which previous studies using proteins could not achieve. The ability of the young rat to utilize the sulfoxide improves with its age, or alternatively there is a process of adaptation to permit more efficient utilization of the sulfoxide. An unexplained increase in the “methionine-like” content of blood plasma accompanies the ingestion of the sulfoxide.