Splanchnic amino acid and glucose metabolism during amino acid infusion in dogs.
With the organ-balance technique, we studied amino acid and glucose metabolism by hepatic and extrahepatic splanchnic tissues in awake dogs in the postabsorptive state and during a 3-h intravenous amino acid infusion. Dogs received a high (1.4 g/kg body wt, n = 5) or low (0.7 g/kg body wt, n = 8) dose of amino acids. In four of the latter dogs, the dose was delivered into a mesenteric vein. During the basal period there was a net removal of gluconeogenic amino acids (particularly alanine), but not branched-chain amino acids, and a net production of glucose by the liver in all dogs. During this time there was a net removal of glucose and production of alanine by the extrahepatic splanchnic tissues. During either high- or low-dose amino acid infusion, net hepatic glucose release increased; despite this, arterial plasma glucose declined due to an increase in tissue glucose uptake at extrasplanchnic sites. The net amount of glucogenic amino acids removed by the liver during high-dose (9.1 +/- 1.0 mmol.kg-1.3 h-1) and low-dose (4.8 +/- 0.6 mmol.kg-1.3 h-1) infusion equaled or exceeded the infused load of these amino acids. In addition, the liver contributed to the net disposal of branched-chain amino acids during high-dose (536 +/- 147 mumol.kg-1.3 h-1) and low-dose (341 +/- 70 mumol.kg-1.3 h-1) infusion. During high-dose infusion, extrahepatic splanchnic tissues participated in the net removal of branched-chain amino acids (436 +/- 162 mumol.kg-1.3 h-1) but not glucogenic amino acids, and net alanine production continued (410 +/- 91 mumol.kg-1.3 h-1).(ABSTRACT TRUNCATED AT 250 WORDS)
Ferrannini
E
E
Department of Medicine, Yale University School of Medicine, New Haven, Connecticut 06510.
DeFronzo
R A
RA
Gusberg
R
R
Tepler
J
J
Jacob
R
R
Aaron
M
M
Smith
D
D
Barrett
E J
EJ
D000596:Amino Acids / Q000097:blood / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D004285:Dogs; D005260:Female; D005934:Glucagon / Q000097:blood; D005947:Glucose / Q000378:metabolism*; D007262:Infusions, Intravenous; D007328:Insulin / Q000097:blood; D008102:Liver Circulation; D008297:Male; D009994:Osmolar Concentration; D014781:Viscera / Q000378:metabolism*
D000596:Amino Acids; D001786:Blood Glucose; D007328:Insulin; D005934:Glucagon; D005947:Glucose