AT1抑制剂,可防止引起血管收缩的信号级联反应的启动;an AT1 inhibitor which prevents the initiation of a signal cascade which causes vasoconstriction;氯沙坦是一种有效的非肽类血管紧张素II受体(AT1)拮抗剂。该受体引发引起血管收缩的信号级联。该受体的拮抗作用通过阻断血管紧张素II的信号进而引起血管舒张。;Losartan is a potent, non-peptide antagonist of angiotensin II receptor, type 1 (AT1). This receptor initiates a signal cascade that causes vasoconstriction. Antagonism of this receptor in turn causes vasodilation by blocking the signal from angiotensin II.