Influence of diet on lactate, alanine and serine turnover and incorporation into glucose in the dog.
Four diets containing 0 to 62% of energy from carbohydrate and 24% to 48% of energy from protein were fed to young dogs. The influence of these diets on the turnover of [U-14C]-L-lactate, [U-14C]-L-alanine and [U-14C]-L-serine and on the incorporation of these gluconeogenic precursors into plasma glucose of the dog was established. Blood lactate levels were lowered when high-protein diets were fed but were not influenced by the level of carbohydrate in the diet or by a 48-hour fast. Plasma alanine and serine levels were elevated in dogs fed the high-protein diets and were lowered by a 48-hour fast. Turnover of lactate was increased in dogs fed high-carbohydrate diets whereas turnover of alanine and serine was increased in dogs fed the high-protein diets. Following a 48-hour fast, 14C-lactate conversion to plasma glucose was lower in dogs fed the high-protein diets than in dogs fed the lower protein diets whereas 14C-alanine and 14C-serine conversion to plasma glucose was increased in dogs fed the high-protein. Thus, the diet consumed altered the relative importance of these gluconeogenic precursors to the maintenance of plasma glucose.
D000409:Alanine / Q000378:metabolism*; D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage*; D004285:Dogs; D005947:Glucose / Q000378:metabolism*; D007773:Lactates / Q000378:metabolism*
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D007773:Lactates; D005947:Glucose; D000409:Alanine