摘要
Metorphamide （Met5-enkephalyl-Arg6-Arg7-Val8-NH2） was an endogenous opioid peptide isolated from bovine candate and human phaeochromocytoma tumour. Weber et al. synthesized the peptide and determined its binding activity to opioid receptors. They found that the peptide has a high affinity to μ subtype and lower k binding activity which is about 50% of the μ binding activity, but has almost
