Effect of linagliptin on cardiac oxidative stress (A), p67phox(B), ACE (C), and MCP-1 mRNA (D) of high salt-loaded DS rats. Each value represents mean ± SEM (n = 7 in Normal Na, n = 11 in Veh, n = 11 in Lin). Abbreviations used are the same as in Figure 1. NS, not significant between groups. Upper panels in (A) indicate representative photomicrographs of cardiac sections stained with dihydroethidium. Upper panels in (B) and (C) indicate representative western blot of p67phox and ACE, respectively. In (D), MCP-1 mRNA levels in individual rats were corrected for GAPDH mRNA levels.