NOS3 and Hypertension: On the other hand, in pathological situations such as hypertension and cerebrovascular accidents, the function/expression/activity of the eNOS isoform is impaired that may contribute to a reduction in blood flow, dysfunctional oxygen/metabolites delivery, massive release of Ca2+, glutamate, ROS, super radicals, and other toxicological agents from the brain tissues in association with a disturbed blood brain barrier [1,139].