Figure 4

Dipyridamole does not alter the low-dose prednisolone safety profile. (a) Tyrosine aminotransferase (TAT) mRNA levels from liver were evaluated by RT-PCR after 10 days of repeat dosing in Lewis rats as indicated. β-Actin was used as the endogenous control, and results are shown as fold increase in TAT mRNA over vehicle. *P < 0.01 versus the vehicle control, ^aP = 1.0, ^bP = 0.01, ^cP = 0.90, ^dP = 0.30 versus the combination. (b) Corticosterone levels in serum were evaluated by ELISA after 10 days of chronic dosing. **P < 0.0001, *P < 0.05 versus the vehicle control; ^aP = 0.03, ^bP = 0.01, ^cP = 0.44, ^dP = 0.98 versus the combination. (c) Thymus weight was measured at the conclusion of the study. **P < 0.0001, *P < 0.01 versus the vehicle control; ^aP = 0.83, ^bP = 0.14, ^cP = 0.06, ^dP = 0.03 versus the combination. (d) Adrenal weights were also evaluated upon study completion. *P < 0.05 versus the vehicle control; ^aP = 0.21, ^bP = 0.98, ^cP = 1.0, ^dP = 0.50 versus the combination. Dipyridamole was dosed at 300 mg/kg. Error bars are + standard error of the mean, and statistical comparison is by analysis of variance with Tukey. Dp, dipyridamole; Pd, prednisolone.