DDIT3 and diabetes mellitus: The results showed that GRP78 and CHOP proteins were significantly elevated in the NDM-IR and DM-IR groups (P < 0.05), and GRP78 and CHOP in the DM-IR group were significantly higher than that in the NDM-IR group (Figures 5(a)–5(c), P < 0.05), indicating that MI/IR induced myocardial ERS enhancement in rats.