fig5

Figure 5. Roles of ROS in CMD. Enzymes responsible for ROS generation mainly include NOX2, NOX4 and XO. Aging, stress overload, IR injury and the sympathetic nervous system affect the generation and accumulation of ROS, which play roles in several pathological mechanisms of CMD^[92]. Moreover, ROS activation could promote pathological mechanisms related to CMD, including Ca²⁺ accumulation, inflammation, thrombosis, angiogenesis, apoptosis and vasoconstriction. CMD: Coronary microvascular dysfunction; ROS: reactive oxygen species; NOX2: NADPH oxidase 2; NOX4: NADPH oxidase 4; XO: xanthine oxidase; IR: ischemia/reperfusion; Ca²⁺: calcium ion.