Abstract:

[Abstract] Objective  To explore the effects of thyroid hormone and complement of levothyroxine (L-thyroxine, L-T4) to pregnant mother on the expression of homeobox gene Nkx6.2 mRNA in rat offspring. Methods  One hundred and twenty Wistar rats were randomly divided into normal control group, hypothyroidism group, hypothyroidism in early pregnancy group (1-17 d) supplied with high dosage, medium dosage and low dosage L-T4 and hypothyroidism in late pregnancy group (18-20 d) supplied with high dosage, medium dosage and low dosage L-T4 (15 rats for each groups). The brain tissues of offspring were taken at gestation day17, postnatal day 0 and postnatal day 20, and the content of Nkx6.2 mRNA was detected by real-time fluorescence quantitative PCR techniques. Results  There was significant difference in Nkx-6.2 expression level between hypothyroidism group and normal control group (P < 0.01). There were significant differences in Nkx-6.2 expression levels between groups with supplement of high dosage, medium dosage and low dosage L-T4 and control group (P < 0.01). Conclusion  The expression of Nkx6.2 mRNA is highly related to the supplemental thyroxine dosage and time impact in hypothyrodism preganant rats.

Key words: Hypothyroidism, Homeobox gene, thyroxine, Real-time fluorescence quantitative PCR