Qi Y F, Che X P
Department of Pharmacology, Faculty of Pharmacy, Xi'an Medical University.
Yao Xue Xue Bao. 1992;27(2):81-5.
Experiments were carried out on the isolated rat phrenic nerve diaphragm preparations and chick biventer cervicis preparations. Cu2+ at cumulative concentrations inhibited muscle contractile response to indirect stimulation without affecting the conductivity of the nerve. The inhibiting action of Cu2+ on the muscle contractile response to indirect stimulation was stronger than that to direct stimulation. Cu2+ did not affect the Ach sensitivity of the chick biventer cervicis muscle. The effects of Cu2+ on neuromuscular transmission were antagonized by Ca2+ and L-cysteine. It is concluded that Cu2+ produces neuromuscular blockade by acting mainly on the presynaptic nerve terminals, binding with the -SH groups of the membrane and thus altering the transmembrane movement of Ca2+ and reducing the release of Ach from the nerve terminals.
实验在离体大鼠膈神经膈肌标本和鸡颈二腹肌标本上进行。累积浓度的Cu2+抑制肌肉对间接刺激的收缩反应，而不影响神经的传导性。Cu2+对肌肉间接刺激收缩反应的抑制作用强于对直接刺激的抑制作用。Cu2+不影响鸡颈二腹肌的乙酰胆碱敏感性。Ca2+和L-半胱氨酸可拮抗Cu2+对神经肌肉传递的作用。结论是，Cu2+主要通过作用于突触前神经末梢，与膜的-SH基团结合，从而改变Ca2+的跨膜运动，减少神经末梢乙酰胆碱的释放，产生神经肌肉阻滞。
