Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 28, 2000
Publication Date: June 20, 2000
Citation: Klemcke, H.G., Vallet, J.L., Christenson, R.K. 2000. Glucocorticoid receptor (GR) mRNA expression in porcine conceptuses [abstract]. Proceedings Endocrine 2000 Society Meeting. p. 102. (Abstract No. 394). Technical Abstract: An experiment was conducted to determine the presence of GR mRNA expression in D 20 porcine embryos (term=114 d) and to ascertain if previously reported increased uterine cortisol (D 15-19; Biol. Reprod. 58:240, 1998) regulated this expression. Pregnant pigs were randomly assigned to one of three treatments [vehicle controls (n=7); metyrapone (Met; 8 mg/kg; n=6); metyrapone + cortisol (Met+Cort; 100 ug/kg; n=6)] and surgically catheterized (jugular catheter for blood withdrawal, subcutaneous catheter for drug administration) on D 8 or 9. Treatments began on D 14 and were applied 3 times daily (0700, 1400, 2100 hr) through D 19. Blood samples were obtained at the same time periods on D 14 and 18. Tissues were surgically obtained on D 20 of gestation. A 496 bp porcine cDNA that was 84% homologous to the 9-alpha exon of the human GR was generated via reverse transcription and polymerase chain reaction procedures. This GR cDNA hybridized with transcripts of 7500 and 4500 bp. GR mRNA was measured using Northern analyses. Plasma cortisol concentrations were reduced by Met (7.3 +/- 2.1 ng/ml; mean +/- SE; p<0.01) when compared with controls (28.1 +/- 2.8) and increased by Met+Cort (16.7 +/- 1.3) when compared with Met (p<0.01). GR mRNA expression was clearly evident in embryos, allantois, and trophoderm. Only in allantoic tissue (30.4 +/- 2.2) was there a decrease (p=0.03) in GR mRNA (4500 by transcript) after Met (20.2 +/- 1.6) that was not reversed by Met+Cort (22.0 +/- 2.4). Cortisol may regulate allantoic GR mRNA expression, but Met itself could have direct effects. The coexistence of intrauterine cortisol and conceptus GR mRNA strongly suggests a potential for cortisol to influence early porcine embryonic development.