Figure 5. The effects of nicorandil in the reversal protocol.

The RVSP (A) and the RV/LV ratio (B) in the vehicle group increased at 21 days after the MCT injection (MCT-21) as compared to the baseline, and additionally increased in the next 2 weeks (MCT-35). Late treatment with nicorandil on days 21–35 prevented the additional increase in these parameters, while these effects were blocked by glibenclamide and l-NAME. ^# P<0.05 and ^## P<0.01 vs. normal control; ^* P<0.05 and ^** P<0.01 vs. vehicle (MCT-35); ^† P<0.05 vs. nicorandil (5.0 mg·kg⁻¹·day⁻¹). (C) The histological findings of the PAs (arrows) in the reversal protocol. Top, HE staining; bottom, EVG staining. Scale bar, 50 µm. (D) Late treatment with nicorandil on days 21–35 prevented further increase in the percent medial wall thickness of the PAs. The indications of the symbols are the same as those in panel (A). (E) Survival analysis in the reversal protocol. Each group comprised 14–15 rats. ^* P<0.05 vs. vehicle.