Fumagalli G, Engel A G, Lindstrom J
Mayo Clin Proc. 1982 Dec;57(12):758-64.
We describe a novel method for estimating the rate of destruction of the acetylcholine receptor (AChR) associated with the motor end-plate in the living animal. After the intramuscular injection of a nontoxic dose of alpha-bungarotoxin that had been monoiodinated with 125I (125I-BGT), the loss of radioactivity from the injected site is monitored by an externally positioned gamma counter. Two days after labeling, the decline of radioactivity in the injected muscle parallels the decline of end-plate specific radioactivity and can be used for the estimation of the degradation rate and half-life of end-plate AChR. Using this method, we measured AChR half-life in normal and in myasthenic rats and found a 2.5-fold decrease of AChR half-life in the myasthenic animals. This in vivo method has potential clinical applications.
我们描述了一种新的方法，用于估计活体动物中与运动终板相关的乙酰胆碱受体（AChR）的破坏速率。在肌肉内注射用125I单碘化的无毒剂量的α-银环蛇毒素（125I-BGT）后，通过外部放置的γ计数器监测注射部位放射性的损失。标记两天后，注射肌肉中放射性的下降与终板比放射性的下降平行，可用于估计终板AChR的降解速率和半衰期。使用这种方法，我们测量了正常大鼠和重症肌无力大鼠的AChR半衰期，发现重症肌无力动物的AChR半衰期下降了2.5倍。这种体内方法具有潜在的临床应用价值。
