Effect of intravenous glucose and lipid on proteolysis and glucose
production in normal newborns.
Denne, Scott C., Cheryl A. Karn, Junying Wang, Edward A. Liechty.
Department of Pediatrics, Indiana University School of Medicine,
Indianapolis, IN 46202
APStracts 2:0064E, 1995.
To determine whether nonprotein substrate can suppress proteolysis in
normal newborns, and to assess the effect of this substrate on
glucose production, the rates of appearance of leucine (reflecting
proteolysis) and glucose were measured in healthy 2 day old full term
newborns during fasting, during an intravenous glucose infusion (5.5
mg/kg/min), during an intravenous lipid infusion (2.5 mg/kg/min), and
during a combined glucose plus lipid infusion (5.5 mg/kg/min glucose
+ 2.5 mg/kg/min lipid). Leucine Ra was not reduced from fasting
values during any of the substrate infusions. Intravenous lipid
infusion alone neither suppressed nor increased glucose production.
In contrast, glucose production was nearly completely suppressed
(90%) during intravenous infusions of glucose, either provided alone
or in combination with lipid; this suppression was achieved at
glucose concentrations of 90mg/dL and insulin concentrations of 6
[mu]U/ml. Thus, normal newborns respond to intravenous glucose with
sustained near complete suppression of glucose production, even at
moderate levels of glycemia and at low insulin concentrations;
however, nonprotein substrate infusion does not result in suppression
of proteolysis. It remains unclear to what extent any potential
regulator can suppress proteolysis in this population.
Received 5 January 1995; accepted in final form 30 March 1995.
APS Manuscript Number E002-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 19 April 1995.