有效并具可逆性的氧化氮合成酶抑制剂，来自于巨噬细胞和内皮细胞。该抑制剂也抑制其它的黄素酶（flavoenzymes）， 如中性粒细胞NADPH氧化酶。 Diphenyleneiodonium chloride (DPI) is an inhibitor of NADPH oxidase and also a potent, irreversible, and time-, temperature-dependent iNOS/eNOS inhibitor. Diphenyleneiodonium chloride (DPI) also functions as a TRPA1 activator and selectively inhibits intracellular reactive oxygen species (ROS). Diphenyleneiodonium chloride (DPI) is an inhibitor of NADPH oxidase and also a potent, irreversible, and time-, temperature-dependent iNOS/eNOS inhibitor. Diphenyleneiodonium chloride (DPI) also functions as a TRPA1 activator and selectively inhibits intracellular reactive oxygen species (ROS).