Enhanced antiopiate activity and enzyme resistance in a peptidomimetic of FMRFamide containing E-2,3-methanomethionine and E-2,3-methanophenylalanine
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- 作者：Malin ; David H. ; Lake ; J. Ronald ; McDermitt ; Linda S. ; Smith ; David A. ; Witherspoon ; Wendi E. ; et. al.
- 关键词：FMRFamide ; NPFF ; NPFF receptors ; Neuropeptide FF ; F8Famide ; Antiopiate peptides ; Cyclopropylogs ; Rat ; Opiate dependence ; Opiate abstinence syndrome
- 刊名：Peptides
- 出版年：1996
- 出版时间：1996
- 年：1996
- 卷：17
- 期：1
- 页码：83-86
- 全文大小：389 K
文摘
FMRFamide is a molluscan peptide that has shown antiopiate activity in a number of mammalian test systems. Peptidomimetics of FMRFamide substituted with conformationally constrained stereoisomers of Z-2,3-methanomethionine or E-2,3-methanomethionine precipitated abstinence syndrome far more potently than FMRFamide itself. The current study determined the effect on antiopiate potency of an additional rigid substitution. A peptidomimetic containing a stereoisomer of E-2,3-methanomethionine was compared with a peptidomimetic additionally substituted at the C-terminal with E-2,3-methanophenylalanine. Morphine abstinence signs were observed after varying doses (0.125-25.0 μg) of these two peptidomimetics were injected into the third ventricle of morphine-dependent rats. The peptidomimetic containing both rigid substitutions was far more potent than the peptidomimetic of FMRFamide containing methanomethionine alone. The increased potency appears to be related to enzyme resistance rather than receptor affinity.