Skip to main content
profile image
Selected Works of John Gieng, PhD
Article
Plasma α1-Acid Glycoprotein Can Be Used to Adjust Inflammation-Induced Hyporetinolemia in Vitamin A-Sufficient, but Not Vitamin A-Deficient or -Supplemented Rats
Journal of Nutrition (2006)
  • Sin H. Gieng, The Pennsylvania State University
  • Francisco J. Rosales, University of Potsdam
Link Find in your library
Abstract
We examined the association between α1-acid glycoprotein (AGP), all-trans-retinol (retinol), and albumin concentrations in a longitudinal animal model of IL-6–induced inflammation. Vitamin A–sufficient (VAS) male Sprague-Dawley rats were administered recombinant human IL-6 [n = 4, 65 μg/(kg·d)] or PBS (n = 4) continuously for 7 d via osmotic minipumps. Plasma samples were obtained daily and concentrations of retinol, AGP, albumin, and total protein were measured. Compared with both baseline and controls, retinol and albumin decreased (P < 0.05), AGP increased (P < 0.05), and total protein concentrations were unaffected in IL-6–treated rats. In vitamin A–deficient (VAD) rats, AGP concentrations were significantly lower at all time points and increased only to one-third of that in VAS rats. The AGP cut-off value indicative of inflammation was 0.11 g/L (i.e., 95% upper limit of baseline concentrations). After 20.5 h, there was an inverse linear correlation between AGP concentrations and the relative change in retinol to baseline (y = −0.18x + 0.48, r = −0.84, P < 0.001). However, changes in AGP and albumin were not correlated (P = 0.94). The application of this function to retinol concentrations in rats from separate experiments showed that hyporetinolemia cannot be adjusted using plasma AGP in VAD or vitamin A–supplemented rats. In conclusion, correcting inflammation-induced hyporetinolemia using an acute-phase protein requires longitudinally derived data, knowledge of vitamin A status, and a common underlying mechanism of change.
Keywords
  • α1-acid glycoprotein,
  • correction factor,
  • hyporetinolemia,
  • inflammation,
  • vitamin A
Disciplines
Publication Date
July, 2006
Publisher Statement
SJSU users: use the following link to login and access the article via SJSU databases.
Citation Information
Sin H. Gieng and Francisco J. Rosales. "Plasma α1-Acid Glycoprotein Can Be Used to Adjust Inflammation-Induced Hyporetinolemia in Vitamin A-Sufficient, but Not Vitamin A-Deficient or -Supplemented Rats" Journal of Nutrition Vol. 136 Iss. 7 (2006) p. 1904 - 1909 ISSN: 0022-3166
Available at: http://works.bepress.com/john-gieng/2/