[Studies on methionine metabolism. 1. Studies on general metabolism and body composition].
19-day trials were carried out with diets containing varying amounts of methionine (0.3%), 0.8%, 1.3%, 2.0%, 2.8%, 5.3%). Diets containing 0.8% methionine were found to have the most favourable effect. Increasing methionine supplementation gradually decreased the food consumption, the daily weight gains and the efficiency of food utilization of the animals. Data on weight gains and food utilization in the "pair-fed" groups were more favourable.  A stepwise decline was observed with regard to the absolute quantity of nitrogen retained (mg) as well as with regard to the quotient (%) of the amount of N retained to the amount of N utilized. Studies on the body composition of the animals showed that all those animals consuming large quantities of methionine did not synthesize protein while the process of protein synthesis in "pair fed" animals was found to be reduced, but still positive. These results suggest the occurrence of disorders in the protein metabolism arising in the organism of the animals in response to the uptake of large amounts of methionine. The relatively low fat content of the bodies of animals receiving excessive amounts of methionine, the increasing losses of fat during the trial as well as decreases in the RQ values indicated an increased rate of fat utilization in these animals. The relative water content of the body of animals receiving excessive quantities of methionine was higher, but, nevertheless, the massive weight decreases were, in the first instance, due to losses of water. Loss of water and fat as well as relative hydratation are characteristic symptoms of malnutrition. These were, to some extent, also observed in "pair fed" animals.
D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001823:Body Composition; D001834:Body Water / Q000378:metabolism; D004734:Energy Metabolism; D008297:Male; D008715:Methionine / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D051381:Rats
D008715:Methionine; D009584:Nitrogen
Untersuchung des Methionin Stoffwechsels. 1. Mitteilung. Untersuchungen zum allgemeinen Stoffwechsel und zur Körperzusammensetzung