Influence of casein and casein hydrolysate diets on nutritional recovery of starved rats.
BACKGROUND
The aim of this study was to compare the effects of two diets, which differed in their protein source (casein and casein hydrolysate), on the nutritional recovery and intestinal repair of undernourished rats at weaning after a 3-day fasting period. Profound alterations in gut structure and signs of malnutrition appeared after the starvation period.


METHODS
The casein hydrolysate was prepared by enzymatic hydrolysis and ultrafiltration. Rats were refed the casein-based or the casein hydrolysate-based diet for 96 hours. Normal-fed male Wistar rats at weaning were given the casein diet for 7 days and were used as controls. Liver acetylcholinesterase, glutamate dehydrogenase activities, serum amino acid profiles, jejunal oligosaccharidases, alkaline phosphatase, and leucine aminopeptidase activities were studied. Intestinal permeability to intact proteins was also tested by using ovalbumin and measuring its concentration in serum.


RESULTS
Intestinal and liver enzyme activities and serum amino acid profiles reached normal values after 96 hours of refeeding, regardless of the diet used. Glutamate dehydrogenase activity remained higher in both diet groups. Intestinal permeability to ovalbumin remained significantly increased only in the group refed the casein diet.


CONCLUSIONS
Our results show that 4 days of refeeding are sufficient for complete intestinal recovery after fasting, provided the dietary protein source is a casein hydrolysate. We suggest that patients with malnutrition or malabsorption syndrome should be fed formula composed of enzymatic protein hydrolysates (because of their low antigenicity) rather than enteral formulas composed of intact proteins.
Boza
J
J
Department of Biochemistry and Molecular Biology, University of Granada, Spain.
Martinez
O
O
Baro
L
L
Suarez
M D
MD
Gil
A
A
D000110:Acetylcholinesterase / Q000378:metabolism; D000596:Amino Acids / Q000097:blood; D000818:Animals; D001835:Body Weight; D002364:Caseins / Q000008:administration & dosage* / Q000627:therapeutic use; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000627:therapeutic use; D005969:Glutamate Dehydrogenase / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism / Q000473:pathology; D007583:Jejunum / Q000201:enzymology; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008297:Male; D009929:Organ Size; D011492:Protein Hydrolysates / Q000008:administration & dosage* / Q000627:therapeutic use; D011506:Proteins / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013217:Starvation / Q000178:diet therapy* / Q000378:metabolism / Q000473:pathology
D000596:Amino Acids; D002364:Caseins; D004044:Dietary Proteins; D011492:Protein Hydrolysates; D011506:Proteins; C026375:trypticase-soy broth; D005969:Glutamate Dehydrogenase; D000110:Acetylcholinesterase