Characterization of the High Affinity [³H]Nociceptin Binding Site in Membrane Preparations of Rat Heart: Correlations with the Non-opioid Dynorphin Binding Site

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• 作者：Dumont ; Michel ; Lemaire ; Simon
• 刊名：Journal of Molecular and Cellular Cardiology
• 出版年：1998
• 出版时间：December, 1998
• 年：1998
• 卷：30
• 期：12
• 页码：2751-2760
• 全文大小：241 K

文摘

The binding parameters of [³H]nociceptin were examined in membrane preparations of rat heart and compared with those of [³H]dynorphin A-(1-13) ([³H]Dyn A-(1-13)). Scatchard analysis of [³H]nociceptin binding revealed the presence of two distinct sites: a high affinity (K_d: 583 nm) low capacity (B_max: 132 pmol/mg protein) site and a low affinity (K_d: 10 316 nm) high capacity (1552 pmol/mg protein) site. Dyn A and related peptides were potent competitors of the binding to the high affinity site with the following rank order of potencyα-neo-endorphin>Dyn A-(2-13)=Dyn A-(3-13)>Dyn A-(5-13)>Dyn A-(1-13)>Dyn A>Dyn B>Dyn A-(6-10)>>Dyn A-(1-8). Nociceptin was 6.7 times less potent than Dyn A with a K_iof 4.8μmas compared with 0.72μmfor Dyn A. The order of potency of the various peptides in inhibiting [³H]nociceptin binding correlated well (r