Effect of a mixed meal on hepatic lactate and gluconeogenic precursor metabolism in dogs.
The present experiments were undertaken to assess lactate and gluconeogenic precursor metabolism in the 30 h following consumption of a mixed meal by the overnight-fasted, conscious dog. The arterial glucose level rose by a maximum of 13 mg/dl 4 h after the meal and had returned to control levels by 12 h. Hepatic glucose production was suppressed for 12 h after feeding, but net hepatic glucose uptake did not occur. The arterial lactate level rose from 0.55 +/- 0.10 to 1.28 +/- 0.14 mM within 1 h of feeding and remained elevated for 12 h. Net hepatic lactate production, measured with an A-V difference technique, rose from 3.5 +/- 2.8 to 19.4 +/- 3.1 mumol X kg-1 X min-1 h after the meal and declined slowly over the next 22 h. The liver then began to consume lactate so that at 30 h net hepatic uptake was 5.7 +/- 0.5 mumol X kg-1 X min-1. The total hepatic uptake of the gluconeogenic amino acids (alanine, glycine, serine, threonine) increased from 5.3 +/- 0.8 to 11.5 +/- 2.5 mumol X kg-1 X min-1 at 1 h and remained elevated for 4 h. The arterial alanine level rose from 0.36 +/- 0.03 to 0.51 +/- 0.04 mM at 2 h and remained elevated for 18 h. Insulin increased from 11 +/- 2 microU/ml to a maximum of 44 +/- 5 4 h after the meal, and the glucagon level rose from 59 +/- 8 pg/ml to a maximum of 150 +/- 22 1 h after feeding.(ABSTRACT TRUNCATED AT 250 WORDS)
D000409:Alanine / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D004285:Dogs; D005260:Female; D005502:Food; D005934:Glucagon / Q000378:metabolism; D005943:Gluconeogenesis; D007328:Insulin / Q000378:metabolism; D007773:Lactates / Q000097:blood / Q000378:metabolism*; D019344:Lactic Acid; D008099:Liver / Q000378:metabolism*; D008102:Liver Circulation; D008297:Male; D013997:Time Factors
D000596:Amino Acids; D001786:Blood Glucose; D007328:Insulin; D007773:Lactates; D019344:Lactic Acid; D005934:Glucagon; D000409:Alanine