Diabetes, Vol 37, Issue 2 237-245, Copyright © 1988 by American Diabetes Association
Splanchnic amino acid and glucose metabolism during amino acid infusion in dogs
E Ferrannini, RA DeFronzo, R Gusberg, J Tepler, R Jacob, M Aaron, D Smith and EJ Barrett
Department of Medicine, Yale University School of Medicine, New Haven, Connecticut 06510.
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)