## 3 Results
### Effects of DEX Administration on the Pituitary Gland of Mice  
At D14-9, the mRNA expression levels of LH and FSH in the DEX-administered group were significantly lower than those in the normal and sham group as follows: LH, 10 ug/kg compared to normal (\(p\) = 0.028), 40 ug/kg compared to normal (\(p\) = 0.041), 10 ug/kg compared to sham (\(p\) = 0.007), and 40 ug/kg compared to sham (\(p\) = 0.01); FSH, 10 ug/kg compared to normal (\(p\) = 0.027), 40 ug/kg compared to normal (\(p\) = 0.027), 10 ug/kg compared to sham (\(p\) = 0.018), and 40 ug/kg compared to sham (\(p\) = 0.018). After D14-13, LH and FSH mRNA expression was not significantly different from that in the normal and sham group (Figure 3A). \(\alpha\)2A-adrenergic receptor mRNA and imidazoline receptor mRNA were expressed in the pituitary gland. At D14-9, the mRNA expression of  
\begin{table}
\begin{tabular}{l c c c c} \hline \hline
**Point** & \multicolumn{4}{c}{**D14-9**} \\ \hline Group & Normal & Sham & 10 ug/kg & 40 ug/kg \\ Average & & N.D. & N.D. & 0.036 & 0.948 \\ (fmol/mL) & N.D. & N.D. & 0.020 & 0.331 \\ \hline Collection time & & & D14-13 & \\ \hline Group & Normal & Sham & 10 ug/kg & 40 ug/kg \\ Average & & N.D. & N.D. & N.D. & 0.054 \\ (fmol/mL) & N.D. & N.D. & N.D. & 0.070 \\ \hline Collection time & & & D15-9 & \\ \hline Group & Normal & Sham & 10 ug/kg & 40 ug/kg \\ Average & & N.D. & N.D. & N.D. \\ (fmol/mL) & N.D. & N.D. & N.D. & N.D. \\ SD & & N.D. & N.D. & N.D. \\ \hline Collection time & & & D15-13 & \\ \hline Group & Normal & Sham & 10 ug/kg & 40 ug/kg \\ Average & & N.D. & N.D. & N.D. \\ (fmol/mL) & N.D. & N.D. & N.D. & N.D. \\ SD & & N.D. & N.D. & N.D. \\ \hline \hline \end{tabular} The blood DEX concentration at each testis collection period was measured by LC/MS. The values are presented as means \(\pm\) standard deviation (SD). The sampling points after 14 days of continuous DEX administration were 9:00 on day 14 (D14-9), 13:00 on day 14 (D14-13), 9:00 on day 15 (D15-9), and 13:00 on day 15 (D15-13). N.D.; not detected.  
\end{table}
Table 1: Blood concentration of DEX in experimental mice.  
\(\alpha\)2A-adrenergic receptors was significantly increased in the DEX-administered group as compared with that in the normal and sham group (\(\alpha\)2A-adrenergic receptor: 10 \(\upmu\)g/kg compared to normal, \(p\) = 0.009; 10 \(\upmu\)g/kg compared to sham, \(p\) = 0.001). However, no changes were observed in imidazoline receptors. After D14-13, there was no significant difference in the mRNA expression levels of \(\alpha\)2A-adrenergic receptors and imidazoline receptors (Figure 3B). Hence, it was found that the mRNA expression of LH and FSH decreased, while the mRNA expression of \(\alpha\)2A-adrenergic receptors increased 2 h after DEX administration. The expression of LH, FSH, and \(\alpha\)2A-adrenergic receptors returned to the same level as in the normal group 6 h after DEX administration. The following factors were statistically significant but were rejected because they did not meet our criteria for significance: LH at D15-13 (10 \(\upmu\)g/kg compared to normal, \(p\) = 0.03) and imidazoline receptor at D15-13 (10 \(\upmu\)g/kg compared to normal, \(p\) = 0.003; 40 \(\upmu\)g/kg compared to normal, \(p\) = 0.02).  
Figure 3: Effect of DEX administration on mouse pituitary gland. (**A**) The expression levels of luteinizing hormone (LH) and follicle-Stimulating Hormone (FSH) at each pituitary gland collection point were measured by RT-PCR. (**B**) The expression levels of \(\alpha\)2A-adrenergic and imidazoline receptors at each pituitary gland collection period were measured by RT-PCR. The values in the graph are presented as means \(\pm\) SDs. * The difference was significant compared with the other group according to the statistical method of this study. The sampling points after 14 days of continuous DEX administration were 9:00 on day 14 (D14-9), 13:00 on day 14 (D14-13), 9:00 on day 15 (D15-9), and 13:00 on day 15 (D15-13).