Free amino acids in diaphragm and in medium after incubation

Range Table - link nmol/mg muscle
Organism Rat Rattus norvegicus
Reference Fulks RM, Li JB, Goldberg AL. Effects of insulin, glucose, and amino acids on protein turnover in rat diaphragm. J Biol Chem. 1975 Jan 10 250(1):290-8. p.293 table IPubMed ID1141208
Method P.293 heading above table I: "Hemidiaphragms of eight fasted rats were preincubated for 30 min and then transferred to fresh medium for a 3-hour incubation. Control tissues were incubated in KRB [Krebs-Ringer bicarbonate] buffer, others in KRB supplemented with glucose, 11 mM, and insulin, 0.1 unit per ml. At the end of the incubation, proteins were removed from muscle homogenates and medium with trichloroacetic acid. The acid-soluble fractions from eight muscles were combined, as were those from the media, and amino acid analyses performed. Net change is the difference between the amino acid content of the muscle and medium of tissues treated with insulin and glucose and the control tissues."
Comments P.292 right column bottom paragraph: "Incubation of the diaphragm in the presence of insulin and glucose was found to inhibit the release of amino acids, including tyrosine, from the muscle (Table I)." P.295 right column bottom paragraph: "The present experiments used diaphragms from young (50 to 80 g) rats, because the muscles are thin and permit rapid diffusion of nutrients. In such growing animals, the diaphragm must be accumulating protein, but upon incubation in KRB, the muscle released amino acids into the medium. These effects could not be accounted for simply by the leakage of materials from the intracellular pools (Table I), but instead reflected net protein catabolism."
Entered by Uri M
ID 113845