重症肌无力血浆免疫球蛋白可降低人终板在体外的微小终板电位。

A myasthenia gravis plasma immunoglobulin reduces miniature endplate potentials at human endplates in vitro.

作者信息

Burges J, Wray D W, Pizzighella S, Hall Z, Vincent A

机构信息

Department of Pharmacology, Royal Free Hospital School of Medicine, London, UK.

出版信息

Muscle Nerve. 1990 May;13(5):407-13. doi: 10.1002/mus.880130507.

DOI:10.1002/mus.880130507

PMID:2345558

Abstract

A particular myasthenia gravis (MG) plasma Ig has previously been shown to block a single alpha-bungarotoxin (alpha-BuTx) binding site on embryonic rat muscle acetylcholine receptor (AChR). We have investigated its effect on embryonic/denervated and adult human AChR both in extracts and in situ. Plasma Ig blocked 125I-alpha-BuTx binding by greater than 85% to the AChR extracted from denervated muscle, but only by 55% to AChR extracted from normal human muscle. Incubation of intact human muscle fibers with the plasma Ig reduced 125I-alpha-BuTx binding to the endplate AChRs by 63%, and substantially decreased the amplitude of miniature endplate potentials. We conclude that anti-alpha-BuTx site antibodies, when present, can be important in the pathophysiology of the disease.

摘要

先前已证明，某一重症肌无力（MG）患者的血浆免疫球蛋白（Ig）可阻断胚胎大鼠肌肉乙酰胆碱受体（AChR）上的单个α-银环蛇毒素（α-BuTx）结合位点。我们已研究了其对提取物和原位的胚胎/去神经支配及成人AChR的影响。血浆Ig使125I-α-BuTx与从去神经支配肌肉提取的AChR的结合阻断率超过85%，但与从正常人类肌肉提取的AChR的结合阻断率仅为55%。用血浆Ig孵育完整的人类肌纤维，可使125I-α-BuTx与终板AChR的结合减少63%，并显著降低微小终板电位的幅度。我们得出结论，抗α-BuTx位点抗体一旦存在，在该疾病的病理生理学中可能很重要。