Glucocorticoid receptor expression and cortisol level in cord blood of term infants

Objective. To examine the expression levels of glucocorticoid receptor (GR) isoforms in peripheral blood mononuclear cells (PBMCs) and serum cortisol levels in cord blood from term infants. Methods. The study population consisted of 172 term infants who were delivered from healthy pregnant women. GRalpha and GRbeta expression levels, and serum cortisol level in cord blood were determined by real-time PCR and ELISA, respectively. Results. Detection rates of GRalpha, GRbeta, and GAPDH were 100%, 63.4%, and 100%, respectively. The expression level of GRalpha was about 200 times that of GRbeta. There were no associations between GR expression level and clinical variables. There were significant associations of low UmApH, maternal gravidity or parity, and vaginal delivery with a high cortisol level; however, there were no correlations between GR expression levels and cortisol level. Conclusions. It is considered that glucocorticoid effects could be expected from the fetal period to the neonatal period, because GRalpha expression level was not related to perinatal factors, GRbeta expression level, and cortisol level in term infants. Further studies of larger populations including very preterm and small for gestational age infants are necessary to determine the balance of expression between GRalpha and GRbeta, and cortisol level.