Effect of nutritional rehabilitation of undernourished rats on serum insulin-like growth factor (IGF)-I and IGF-binding proteins.
The aim of the present work was to study the effect of nutritional rehabilitation with different concentration of dietary protein (6, 18 or 50%) of previously undernourished rats on serum Insulin-like growth factor-I (IGF-I) and Insulin-like growth factor binding proteins levels (IGFBPs). Undernutrition was induced by feeding rats with 0.5% casein diet for 5 weeks. Over this period, growth, serum total proteins, IGF-I levels and IGFBP-3/IGFBP-2 ratio were significantly decreased compared to the group fed ad libitum 18% casein diet. Nutritional rehabilitation for 21 days with 6% casein diet did not change any of these parameters. Nutritional rehabilitation with 18 or 50% casein diet for one day did not initiate the restoration of serum IGF-I levels and IGFBP-3/IGFBP-2 ratio. However, after 10 days with 18 or 50% casein diets, there was an increase of 12 fold in IGF-I levels and 7 fold in the IGFBP-3/IGFBP-2 ratio. Finally, rehabilitation for 21 days with 18 or 50% casein diet produced an increase of 21 and 26 fold in IGF-I levels, and 6.1 and 14.5 fold in the IGFBP-3/IGFBP-2 ratio respectively. These results suggest that nutritional rehabilitation with 18% casein and above were more effective than 6% casein diets to reestablish body weight. Serum IGF-I and IGFBP-3 concentrations were sensitive indicators of the evolution of the nutritional status of the rats depending of the protein concentration in the diet in previously undernourished rats.
Departamento de Fisiología de la Nutrición, Instituto Nacional de la Nutrición, México, D.F., México.
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Tovar
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Halhali
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Torres
D000818:Animals; D001798:Blood Proteins / Q000032:analysis; D001835:Body Weight; D002364:Caseins / Q000627:therapeutic use; D004044:Dietary Proteins / Q000008:administration & dosage / Q000627:therapeutic use; D002149:Energy Intake; D005246:Feedback; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000097:blood*; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008297:Male; D009929:Organ Size; D011488:Protein Deficiency / Q000097:blood* / Q000178:diet therapy*; D051381:Rats; D017208:Rats, Wistar; D013623:Tail / Q000473:pathology
D001798:Blood Proteins; D002364:Caseins; D004044:Dietary Proteins; D018971:Insulin-Like Growth Factor Binding Protein 2; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I