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.
Tovar
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AR
Departamento de Fisiología de la Nutrición, Instituto Nacional de la Nutrición, México, D.F., México.
Halhali
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A
Torres
N
N
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