Fig. 3.

Changes of Sp1 and Sp3 expression in the nuclei of rat livers during restraint stress. The expression of Sp3, a negative factor for cbs transcription, was found to be increased in hepatocytes nuclei of stressed rats, the ratios (stress/control) of relative densitometry were 1.31, 1.76, 1.89 and 1.84 for stress lasting 6 h, 1 weeks, 2 weeks and 3 weeks, respectively. But Sp1, a positive transcription factor for cbs, remained almost unchanged after stress. That is Sp1/Sp3 ratios decreased in stressed rat liver cells when compared with control. β-Actin was used as an internal control, and the changed ratio of proteins is normalized by β-actin based on OD value of proteins bands. Graphical representations of Sp1 and Sp3 are shown in the bottom panel with changes in expression over time (n = 3, *, p < 0.05 compared with control)