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United States Department of Agriculture

Agricultural Research Service

Title: Relationships of Plasma Cortisol and Corticosteroid-Binding Globulin (Cbg) Concentrations, and Hepatic Cbg Mrna Expression Levels in Fetal and Postnatal Pigs

Authors
item Heo, J - UNIVERSITY OF TENNESSEE
item Kattesh, H - UNIVERSITY OF TENNESSEE
item Matteri, Robert
item Roberts, M - UNIVERSITY OF TENNESSEE

Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: July 28, 2000
Publication Date: N/A

Technical Abstract: The concentrations of CBG in plasma are determined by hepatic synthesis, peripheral degradation, and/or transfer to the extravascular system. The purpose of this study was to evaluate the relationships among CBG mRNA expression in liver, plasma CBG levels, and cortisol concentrations during fetal and postnatal periods in the pig. A partial CBG cDNA (500bp) probe was developed from porcine liver RNA using RT-PCR. The porcine CBG cDNA sequence showed 77% and 82% homology with the human and sheep CBG cDNA sequences, respectively. Blood and liver tissues were collected from the fetal pigs (n=7-14) on d50, d70, d80, d90, and d104 of gestation, as estimated by fetal length, and from postnatal pigs (n=7-8) on d1, d3, d10, d20, d30, and d40 following birth. Plasma cortisol and CBG concentrations were determined by RIA and ELISA, respectively. Total RNA was isolated from liver tissue. Levels of CBG mRNA were determined by Northern blot analysis and expressed relative to beta-actin mRNA. CBG mRNA levels were negatively correlated to gestational age (r=-0.63, p<0.001). CBG mRNA expression was highest on d50 compared to d90 (p<0.005). Plasma CBG concentrations were highly correlated to CBG mRNA levels (r=0.90, p<0.01). Plasma cortisol concentrations were not different over this same period. In the postnatal period the CBG mRNA levels were positively correlated to age (r=0.75, p<0.001). CBG mRNA expression increased (p<0.001) from its lowest value on d3 to its highest level on d40. Plasma CBG concentration increased (p<0.001) on d10 compared to d1. Plasma cortisol concentrations remained constant during this postnatal period. This study represents the first determination of the relationship between the abundance of hepatic CBG mRNA and circulating CBG concentrations in the pig.

Last Modified: 11/27/2014
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