HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 291/6/E1333    most recent 00028.2006v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Brown, L. D. Articles by Hay, W. W. Search for Related Content PubMed PubMed Citation Articles by Brown, L. D. Articles by Hay, W. W., Jr.

Effect of hyperinsulinemia on amino acid utilization and oxidation independent of glucose metabolism in the ovine fetus

Perinatal Research Center and Department of Pediatrics, University of Colorado Health Sciences Center, Aurora, Colorado

Submitted 7 June 2006 ; accepted in final form 29 June 2006

We studied the effect of acute hyperinsulinemia on amino acid (AA) utilization and oxidation rates independent of insulin-enhanced glucose metabolism in fetal sheep. Metabolic studies were conducted in each fetus (n = 11) under three experimental periods. After control period (C) study, a fetal hyperinsulinemic-euglycemic-euaminoacidemic (HI-euG-euAA) clamp was established, followed by a hyperinsulinemic-hypoglycemic-euaminoacidemic (HI-hypoG-euAA) clamp to decrease glucose metabolic rates toward C values. Infusions of ³H₂0, L-[1-¹³C]leucine, and [¹⁴C(U)]glucose were administered to measure blood flow, leucine oxidation, and fetal glucose uptake, utilization, and oxidation in each period. Fetal glucose utilization rate increased 1.7-fold with hyperinsulinemia (C 5.8 ± 0.8 mg·kg^–1·min^–1, HI-euG-euAA 10 ± 1.3 mg·kg^–1·min^–1, P < 0.0001), returning to rates not different from C with hypoglycemia (HI-hypoG-euAA 7.1 ± 0.9 mg·kg^–1·min^–1 vs. C value, P = 0.15). Fetal glucose oxidation rate increased 1.7-fold with hyperinsulinemia (C 3.1 ± 0.2 mg·kg^–1·min^–1, HI-euG-euAA 5.4 ± 0.4 mg·kg^–1·min^–1, P < 0.0001) and decreased to near control rates with hypoglycemia (4.0 ± 0.3 HI-hypoG-euAA vs. C value, P = 0.006). AA utilization rates increased with hyperinsulinemia for all essential and most nonessential AAs (P < 0.001) and did not change when insulin-induced increases in glucose utilization returned to control rates. Leucine oxidation rate increased 1.7-fold with hyperinsulinemia (C 1.0 ± 0.3 µmol·min^–1·kg^–1, HI-euG-euAA 1.7 ± 0.3 µmol·min^–1·kg^–1, P < 0.002) and did not change when glucose oxidation rate was decreased with hypoglycemia. These results demonstrate that, in fetal sheep, insulin promotes AA utilization and oxidation independent of its simultaneous effects on glucose metabolism. In acute hyperinsulinemic conditions, AA oxidation does not change when insulin-induced glucose utilization is prevented.

insulin; leucine; fetal sheep

This article has been cited by other articles:

				P. J. Rozance, M. M. Crispo, J. S. Barry, M. C. O'Meara, M. S. Frost, K. C. Hansen, W. W. Hay Jr., and L. D. Brown Prolonged maternal amino acid infusion in late-gestation pregnant sheep increases fetal amino acid oxidation Am J Physiol Endocrinol Metab, September 1, 2009; 297(3): E638 - E646. [Abstract] [Full Text] [PDF]

				L. D. Brown, P. J. Rozance, J. S. Barry, J. E. Friedman, and W. W. Hay Jr. Insulin is required for amino acid stimulation of dual pathways for translational control in skeletal muscle in the late-gestation ovine fetus Am J Physiol Endocrinol Metab, January 1, 2009; 296(1): E56 - E63. [Abstract] [Full Text] [PDF]