Effect of protein malnutrition on neutral amino acid transport by rat hepatocytes during development.
Hepatocytes from suckling rats whose mothers were fed a low-protein diet (9% protein) showed a lower capacity for Na(+)-dependent L-alanine uptake [due to a decrease in maximal uptake rate (Vmax) of a low-affinity component of transport] and were not able to respond to insulin or glucagon, whereas those from suckling pups whose mothers were fed the control diet (17% protein) had already developed the ability to upregulate L-alanine transport after hormone treatment. When animals from low-protein-fed mothers were weaned onto a hypoprotein diet, the overall capacity for Na(+)-dependent L-alanine uptake (apparent Vmax) and its responsiveness to pancreatic hormones were restored. Hepatocytes from these animals showed a lower response to glucocorticoid treatment. Amino acid availability was dramatically decreased in suckling and weanling rats fed a low-protein diet. These results support the hypothesis that nutrient supply is an important factor in the proper development of hepatic transport functions during the suckling-weaning transition.
Gomez-Angelats
M
M
Departament de Bioquímica i Fisiologia, Universitat de Barcelona, Spain.
Ruiz-Montasell
B
B
Felipe
A
A
Marín
J J
JJ
Casado
F J
FJ
Pastor-Anglada
M
M
D000375:Aging / Q000378:metabolism; D000409:Alanine / Q000493:pharmacokinetics; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D000833:Animals, Suckling; D001692:Biological Transport; D001769:Blood / Q000378:metabolism; D002478:Cells, Cultured; D004435:Eating; D005934:Glucagon / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D008099:Liver / Q000033:anatomy & histology / Q000166:cytology / Q000378:metabolism*; D009929:Organ Size; D011502:Protein-Energy Malnutrition / Q000378:metabolism*; D051381:Rats; D012964:Sodium / Q000494:pharmacology
D000596:Amino Acids; D007328:Insulin; D005934:Glucagon; D012964:Sodium; D000409:Alanine