Format

Send to

Choose Destination
See comment in PubMed Commons below
Am J Physiol. 1988 Sep;255(3 Pt 1):E366-73.

Physiological hypercortisolemia increases proteolysis, glutamine, and alanine production.

Author information

  • 1Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110.

Abstract

Physiological elevations of plasma cortisol levels, as are encountered in stress and severe trauma, were produced in six normal subjects by infusing them with 140 micrograms.kg-1.h-1 of hydrocortisone for 64 h. Amino acid kinetics were measured in the postabsorptive state using three 4-h infusions of L-[1-13C]leucine, L-[phenyl-2H5]-phenylalanine, L-[2-15N]glutamine, and L-[1-13C]alanine tracers 1) before, 2) at 12 h, and 3) at 60 h of cortisol infusion. Before and throughout the study, the subjects ate a normal diet of adequate protein (0.8 g.kg-1.day-1) and energy intake. The cortisol infusion raised plasma cortisol levels significantly from 10 +/- 1 to 32 +/- 4 micrograms/dl, leucine flux from 83 +/- 3 to 97 +/- 3 mumol.kg-1.h-1, and phenylalanine flux from 34 +/- 1 to 39 +/- 1 (SE) mumol.kg-1.h-1 after 12 h of cortisol infusion. These increases were maintained until the cortisol infusion was terminated (64 h). These nearly identical 15% increases in two different essential amino acid appearance rates are reflective of increased whole body protein breakdown. Glutamine flux rose from 325 +/- 28 to 453 +/- 28 mumol.kg-1.h-1 by 12 h of cortisol infusion and remained elevated at the same level at 64 h. The increase in flux was primarily due to a 55% increase in glutamine de novo synthesis. Alanine flux increased from 207 +/- 13 to 285 +/- 23 mumol.kg-1.h-1 with acute hypercortisolemia and increased further to 475 +/- 59 mumol.kg-1.h-1 at 60 h of cortisol infusion, a result primarily of increased alanine de novo synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

PMID:
3048115
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Write to the Help Desk