Figure 3: Paricalcitol can improve the expression of fibroblast growth factor-23 (FGF23)-fibroblast growth factor receptor-1 (FGFR1)-Klotho suppressed by isoproterenol-induced myocardial lesions. (a and b) Injection of isoproterenol in rats suppressed the expression of FGF23 in the heart. After paricalcitol treatment, FGF23 expression increased and was significantly restored compared to that in the control group. (c and d) Injection of isoproterenol in rats suppressed the expression of FGFR1 in the heart. After paricalcitol treatment, FGFR1 expression increased and was significantly restored compared to that in the control group. (e and f) Injection of isoproterenol in rats suppressed the expression of Klotho in the heart. Paricalcitol treatment did not significantly restore Klotho expression compared to 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.