AGTR1 and Cerebral ischemia: Cerebral ischemia results in enhanced expression of contractile cerebrovascular receptors, such as endothelin type B (ETB), 5-hydroxytryptamine type 1B (5-HT1B), angiotensin II type 1 (AT1) and thromboxane (TP) receptors in the cerebral arteries within the ischemic area.