The paradoxical response of cardiac glycogen to oral casein hydrolysate in rats.
In fasted rats, casein hydrolysate administration resulted in a marked increase in glycogen synthase I activity, no change in phosphorylase a and a marked decrease in glycogen concentration. This occurred with doses as small as 0.5 g/kg body weight. The major reason for an increase in synthase I appeared to be the reduced glycogen concentration, although insulin may play a role early in the time course. The decrease in glycogen in the absence of a change in phosphorylase a most likely is due to a decrease in an allosteric inhibitor. The nature of this inhibitor is unknown.
D000284:Administration, Oral; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002364:Caseins / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006003:Glycogen / Q000378:metabolism*; D006006:Glycogen Synthase / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D008297:Male; D009132:Muscles / Q000201:enzymology / Q000378:metabolism; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism*; D006005:Phosphorylases / Q000378:metabolism; D011492:Protein Hydrolysates / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D001786:Blood Glucose; D002364:Caseins; D007328:Insulin; D011492:Protein Hydrolysates; C026375:trypticase-soy broth; D006003:Glycogen; D006005:Phosphorylases; D006006:Glycogen Synthase