EDN1 and Stroke: Since IGF-1 is a known neuroprotectant for stroke in young and aging animals, we next investigated IGF-1 levels in serum and corticostriatal samples from ischemic and non-ischemic hemispheres Consistent with previous reports [19, 20, 22, 36–38], ET-1 induced MCAo elevated IGF-1 level in ischemic hemisphere in the control (69%) and NaB treated (61%) (Fig. 7a).