NOS3 and brain ischemia: Thus, the role of eNOS has been extensively studied using animal models of cerebral ischemia, and it has been shown that a transient 90-minute left-sided middle cerebral artery occlusion (MCAO)-induced focal ischemia followed by 24 hours of reperfusion significantly attenuates eNOS expression within the left or ipsilateral RVLM when compared to the abundance of eNOS within the contralateral RVLM [183].