The existence of Endogenous Opioid Peptide (EOP) has been known for a long time, and it has been recognized that EOP has a central paregoric effect and can regulate cardiovascular functions.

• 人们早已知道内源性阿片肽（Endogenous Opioid Peptide，EOP）及阿片受体的存在，并已认识到其在中枢镇痛、中枢心血管功能调节等方面的作用。