Metabolic changes during early starvation in rats fed a low-protein diet in the postweaning growth period.
Metabolic changes during the first 24 hours of starvation were studied in rats previously adapted for 3 weeks during the postweaning growth period to a low-protein diet using lactalbumin as a dietary protein source. Previous adaptation to a high-quality, low-protein diet reduced the effects of early starvation on the loss of body and liver weight. In rats fed a low-protein diet (6% lactalbumin, LP rats), free triiodothyronine (T3) concentration remained higher than in control rats (13% lactalbumin, C rats) throughout the experiment (+38%, 24 hours), and the plasma insulin concentration, which was lower than in C rats during the first 6 hours (-56%), was not different thereafter. Plasma insulin to glucagon molar ratio was lower (-54%) and liver cyclic adenosine monophosphate (cAMP) concentration was higher (+28%) in LP than in C rats in the fed state, but these were not different at 24 hours of starvation. Plasma glucose concentration was slightly lower in LP than in C rats (-15%) in the fed state, but it was not different in both groups during starvation. Whereas they were unchanged in the fed state, plasma lactate concentration was lower (-57%) and free fatty acid and total ketone body concentrations were higher (+38% and +183%, respectively) in LP than in C rats at 24 hours of starvation.(ABSTRACT TRUNCATED AT 250 WORDS)
Claeyssens
S
S
Groupe de Biochimie et de Physiopathologie Digestive et Nutritionnelle, Saint-Etienne du Rouvray, France.
Lavoinne
A
A
Vaillant
C
C
Rakotomanga
J A
JA
Bois-Joyeux
B
B
Peret
J
J
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D004044:Dietary Proteins / Q000008:administration & dosage*; D006019:Glycolysis; D006706:Homeostasis; D006728:Hormones / Q000097:blood; D008297:Male; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000032:analysis; D011770:Pyruvate Kinase / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D013217:Starvation / Q000378:metabolism*; D014886:Weaning
D001786:Blood Glucose; D004044:Dietary Proteins; D006728:Hormones; D011770:Pyruvate Kinase; D010729:Phosphoenolpyruvate Carboxykinase (GTP)