The present study was undertaken to investigate whether the glucocorticoid receptor -alpha (GR-alpha) and -beta (GR-beta) mRNA may be expressed in thyroid gland. Ten normal thyroid gland and 14 follicular adenomas were studied using a real-time fluorescent quantitative RT-PCR (FQ-RT-PCR) method. The results demonstrated that there was a lower expression of GR-alpha mRNA (x10(6) GR-alpha cDNA copies/microg total RNA) in thyroid adenoma (1.27+/-0.26) than that in normal thyroid gland (3.53+/-1.22) (p < 0.001). The expression of GR-beta mRNA was lower in all the thyroid tissues. Of note, there was a significant difference in GR-beta mRNA expression (x10(4) GR-beta cDNA copies/microg total RNA) between thyroid adenoma (80.8+/-13.9) and thyroid gland (1.78+/-0.59) (p < 0.001). The GR-alpha/GR-beta ratios in thyroid adenoma and normal thyroid gland were 1.67+/-0.68 and 207.57+/-84.41 respectively (p < 0.001). These results revealed, for the first time, that both GR-alpha and GR-beta mRNA expression were detectable in both thyroid gland and adenomas tissues. We therefore conclude that down-regulation of GR-alpha and up-regulation of GR-beta mRNA expression may play an important role in the thyroid adenomas.