Journal of Lipid Research, Vol 16, 19-27, Copyright © 1975 by Lipid Research, Inc.
Splanchnic and hepatic triglyceride secretion during hypercaloric intravenous glucose infusion in conscious swine
BM Wolfe and LW Belbeck
We have validated a radiochemical technique for measuring the rate of
secretion of plasma triglycerides from the liver and/or splanchnic region
during the consumption of glucose under isotopic steady-state conditions.
Values obtained with this technique correlated closely with those based on
transhepatic or transsplanchnic chemical gradients (r = 0.95). Likewise,
values for secretion of triglycerides obtained with the radiochemical
technique correlated closely with those obtained for extrahepatic or
extrasplanchnic triglyceride clearance. Values for mean net splanchnic and
hepatic secretion of plasma triglyceride fatty acids, transported
essentially in very low density lipoproteins, were 1.9 and 2.0
mumoles/min.kg body wt0.75, respectively, about one-half of the rate of
transport of free fatty acids. However, the fraction of triglyceride fatty
acids of plasma very low density lipoproteins that was derived from plasma
free fatty acids averaged 9% and that derived from glucose, though
increasing with time, reached only 2% after constant intravenous infusion
of radioglucose for 5 hr. Porcine hepatic secretion of plasma triglycerides
is large in the glucose-fed state, and the secreted triglyceride fatty
acids evidently are derived from stored fat or glycon.