Figure 4: Paricalcitol can improve the expression of vitamin D receptor (VDR) suppressed by isoproterenol. (a and b) Injection of isoproterenol in rats caused heart failure and suppressed the expression of VDR. After treatment with paricalcitol, the expression of VDR improved and returned to a level same as that in the control group. Statistical values are presented as mean ± standard error of the mean; n = 9. *P < 0.05 compared to the control group, #P < 0.05 compared to the isoproterenol group.