In SM of rats with T2D, hyperoxia decreased eNOS protein by 46.2% (1.4 ± 0.13 vs. 2.6 ± 0.2 ng/mg protein, p = 0.002) and increased arginase protein by 2.3‐fold (1.04 ± 0.05 vs. 0.31 ± 0.07 ng/mg protein, p < 0.001) but did not affect iNOS protein. Here, NOS2 is linked to type 2 diabetes mellitus.