Value of dietary protein for hyperplastic growth at restricted energy intakes.
The study describes three experiments of similar design relating dietary protein to growth over a period of 16 days in rats prematurely weaned at 19 days of age. In experiment 1, group 1 was fed ad libitum a 10% caseindiet. Group 2 was pair-fed an isoenergetic 40% casein diet. Groups 3 and 4 received 3 g of the 10% casein and 40% casein diets, respectively. The experiment demonstrated that protein may be used to sustain growth when energy intake is restricted. In experiment 2, all rats were given 3 g of diet per day. Group 1 was given the 10% casein diet, group 2 the 40% casein diet, group 3 a diet with 10% casein plus 30% of a mixture of dispensable amino acids and group 4 the 10% casein diet plus an energy supplement. Results showed that amino nitrogen seems to be a requisite for organ protein synthesis. In experiment 3, group 1 ate the 10% casein diet, group 2 the amino acid-supplemented diet and group 3 the latter minus glycine. Group 3 showed increased liver and kidney growth. The inclusion of glycine in group 2 caused a further increment in organ protein content.
D000818:Animals; D001823:Body Composition; D002364:Caseins / Q000008:administration & dosage*; D004247:DNA / Q000378:metabolism; D004032:Diet; D004044:Dietary Proteins / Q000008:administration & dosage; D002149:Energy Intake; D005998:Glycine / Q000494:pharmacology; D006128:Growth; D006965:Hyperplasia; D007668:Kidney / Q000254:growth & development; D008099:Liver / Q000254:growth & development; D024510:Muscle Development; D011506:Proteins / Q000378:metabolism; D051381:Rats; D014018:Tissue Distribution; D014886:Weaning
D002364:Caseins; D004044:Dietary Proteins; D011506:Proteins; D004247:DNA; D005998:Glycine