Lavidis N A
Department of Physiology, University of Sydney, N.S.W., Australia.
Eur J Pharmacol. 1995 Mar 24;276(1-2):71-6. doi: 10.1016/0014-2999(95)00007-8.
The effects of dynorphin-A, dermorphine and morphine on the secretion of transmitter from the toad (Bufo marinus) motor nerve terminal have been determined. Intracellular recordings of miniature end plate potentials (m.e.p.p.s) and evoked end plate potentials (e.p.p.s) were used to estimate quantal content (m) and binomial parameters p and n. Dynorphin-A, and to a lesser extent morphine, decreased (m) while dermorphine had no significant effect on m. Dynorphin-A (ED50 = 24 microM) was 21 times more potent then morphine (ED50 = 510 microM) in decreasing m. The decrease in m produced by dynorphin-A and morphine was accompanied by a greater decrease in the variance (S2) of number of quanta secreted per stimulation over the recording period. The decrease in m produced by dynorphin-A, and to a lesser extent by morphine, is probably mediated by the opiates acting on kappa-opioid receptors.
已确定强啡肽A、皮啡肽和吗啡对蟾蜍（海蟾蜍）运动神经末梢递质分泌的影响。利用微小终板电位（m.e.p.p.s）和诱发终板电位（e.p.p.s）的细胞内记录来估计量子含量（m）以及二项式参数p和n。强啡肽A以及程度稍轻的吗啡会降低（m），而皮啡肽对m没有显著影响。强啡肽A（ED50 = 24 microM）在降低m方面的效力是吗啡（ED50 = 510 microM）的21倍。强啡肽A和吗啡导致的m降低伴随着记录期间每次刺激分泌的量子数量方差（S2）的更大幅度降低。强啡肽A以及程度稍轻的吗啡导致的m降低可能是由作用于κ-阿片受体的阿片类药物介导的。
