查看文章

Khan, S. and M. E. Smith. Actions of β-endorphin peptides on the contractions of mouse diaphragm muscle. Peptides 18(1) 87–92, 1997.—The effect of derivatives of β-endorphin on the contractile response to indirect stimulation in mouse diaphragm muscle was studied to determine whether the action of the peptide to increase muscle tension is an opioid effect. β-Endorphin(1–27), β-endorphin(30–31), and a β-endorphin(28–31) analogue all increased the amplitude of the contractions. The C-terminal peptides were more potent than β-endorphin or β-endorphin(1–27). The β-endorphin(28–31) analogue, like β-endorphin, decreased the time to peak but β-endorphin(1–27) did not. The effect of β-endorphin(1–27), but not that of the β-endorphin(28–31) analogue, was blocked by naloxone. Thus, β-endorphin acts on muscle via both opioid and nonopioid receptors.