Hepatic histidase gene expression responds to protein rehabilitation in undernourished growing rats.
We studied the effect of nutritional rehabilitation with a 6, 18 or 50% casein diet in undernourished rats on histidase (Hal) expression. Undernutrition was induced by feeding rats a 0.5% casein diet for 5 wk. Over this period, growth, serum total proteins and insulin-like growth factor-I (IGF-I) levels were significantly lower than those of rats that freely consumed an 18% casein diet. During this period, undernutrition also significantly reduced Hal activity and Hal-mRNA concentration. Nutritional rehabilitation for 21 d with a 6% casein diet did not change any of these variables. Nutritional rehabilitation with an 18 or 50% casein diet for 1 d initiated the restoration of Hal activity and mRNA concentration. After 10 d of consuming 18 or 50% casein diets, Hal activity was 5- and 14-fold, and mRNA concentration was 8.5- and 23-fold higher, respectively, than in the protein-undernourished group (PU). During this period, body weight, total serum proteins and IGF-I levels were also significantly (P < 0.05) higher than those of the PU group. At the end of 21 d of rehabilitation with an 18 or 50% casein diet, Hal activity was 14- and 31-fold higher and Hal mRNA concentration was 10- and 24-fold higher, respectively, than in the PU group. In conclusion, our data showed that rehabilitation of undernourished rats with a 6% casein diet was not sufficient to re-establish growth indicators, Hal activity or gene expression, and that nutritional rehabilitation with an 18 or 50% casein diet effectively re-established body weight , biochemical variables and the capacity of histidase gene expression to eliminate the excess of protein.
Tovar
A R
AR
Departamento de Fisiología de la Nutrición, Instituto Nacional de la Nutrición,"Salvador Zubirán" México, D.F. México, 14000, USA.
Santos
A
A
Halhali
A
A
Bourges
H
H
Torres
N
N
D000704:Analysis of Variance; D000818:Animals; D001798:Blood Proteins / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D002364:Caseins / Q000008:administration & dosage; D004044:Dietary Proteins / Q000627:therapeutic use*; D015971:Gene Expression Regulation, Enzymologic; D006638:Histidine Ammonia-Lyase / Q000235:genetics* / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009929:Organ Size / Q000187:drug effects; D011502:Protein-Energy Malnutrition / Q000178:diet therapy* / Q000201:enzymology / Q000534:rehabilitation; D051381:Rats; D017208:Rats, Wistar
D001798:Blood Proteins; D002364:Caseins; D004044:Dietary Proteins; D007334:Insulin-Like Growth Factor I; D006638:Histidine Ammonia-Lyase