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D‐Methionine Utilization in Young Miniature Pigs, Adult Rabbits, and Adult Dogs
Author(s) -
Cho Ei Soon,
Andersen Dean W.,
Filer L. J.,
Stegink Lewis D.
Publication year - 1980
Publication title -
journal of parenteral and enteral nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.935
H-Index - 98
eISSN - 1941-2444
pISSN - 0148-6071
DOI - 10.1177/0148607180004006544
Subject(s) - methionine , medicine , zoology , biology , biochemistry , amino acid
Rats and chickens, unlike man, utilize D‐methionine efficiently. We have studied urinary excretion of methionine isomers in young miniature pigs, adult rabbits, and adult dogs given D‐methionine in an attempt to find an animal model that, like man, utilizes the D‐isomer poorly. Six‐week‐old miniature pigs ingesting a protein‐free diet were infused with 8.5% amino acid solutions differing only in methionine isomer content (L‐ VS DL‐) to supply amino acid requirements. Each solution was infused for a 2‐ or 3‐day period in a cross‐over design. Plasma methionine levels were significantly higher (p = 0.01) during infusion of the solution providing DL‐methionine, with 25% of total plasma methionine present as the D‐configuration. However, urinary methionine excretion was similar with both solutions, with D‐methionine utilization calculated as greater than 99%. Adult rabbits ingesting DL‐methionine (0.14 g/100 g food) showed good utilization of D‐methionine, excreting > 1.3% D‐isomer in the urine. Mixed breed dogs given 1.25 g D‐methionine in their drinking water excreted >0.4% of ingested D‐methionine in the urine. These data indicate that the pig, rabbit, and dog utilize D‐methionine efficiently, behaving like the rat and chicken rather than man.