The action of 1-pyrene-butyrylcholine, a new cholinergic fluorescent probe, has been studied at the cellular level using electrophysiological and fluorescence techniques. The spectroscopic properties of the probe were found to be similar to those pf pyrene-butyric acid, the excited-state lifetime in air-saturated aqueous solutions being 92 nsec. At micromolar concentrations the probe was found to exert a nondepolarizing, reversible blocking action at the neuromuscular junction of the frog. The same cholinolytic effect was observed in hypersensitive denervated muscles. The synaptic localization of the probe could be observed with fluorescence microscopy using sub- and micromolar concentrations. Treatment of the nerve-muscle preparations with proteolytic enzymes, resulting in the separation of the nerve ending from the muscle end-plate, enabled a distinction to be made between the fluorescence arising from these two parts of the synapse. Intense presynaptic fluorescence was observed, and was not altered by micromolar concentrations of alpha-bungarotoxin, d-tubocurarine, hemicholinium, or cholinesterase inhibitors. Faint reversible staining of the end-plate region was observed in enzymically treated muscles and was inhibited by prior treatment with alpha-bungarotoxin. Fluorescent alpha-toxin revealed similar patterns of fluorescence in the end-plate of enzyme-treated muscles. The postsynaptic localization of the fluorescent probe is therefore tentatively identified as the one producing the cholinolytic effect upon binding to acetylcholine receptor sites.

中文翻译：

---

1-P-丁酰胆碱：胆碱能系统的荧光探针。

1-pyrene-butyrylcholine，一种新的胆碱能荧光探针的作用，已在细胞水平使用电生理和荧光技术进行了研究。发现该探针的光谱性质类似于pf丁酸，在空气饱和水溶液中的激发态寿命为92纳秒。在微摩尔浓度下，发现该探针在青蛙的神经肌肉接头处发挥非去极化，可逆的阻断作用。在高度敏感的神经支配的肌肉中观察到相同的胆碱溶解作用。可以使用亚摩尔浓度和微摩尔浓度的荧光显微镜观察探针的突触定位。用蛋白水解酶处理神经肌肉制剂，导致神经末梢与肌肉终板分离，可以区分突触的这两个部分产生的荧光。观察到强烈的突触前荧光，并且不会被微摩尔浓度的α-邦加毒素，d-微管尿素，hemicholinium或胆碱酯酶抑制剂改变。在酶处理过的肌肉中观察到了终板区域的微弱可逆染色，并通过事先用α-真菌毒素进行了抑制。荧光α-毒素在酶处理过的肌肉的终板中显示出相似的荧光模式。因此，暂时将荧光探针的突触后定位鉴定为在结合乙酰胆碱受体位点时产生胆碱分解作用的一种。观察到强烈的突触前荧光，并且不会被微摩尔浓度的α-邦加毒素，d-微管尿素，hemicholinium或胆碱酯酶抑制剂改变。在酶处理过的肌肉中观察到了终板区域的微弱可逆染色，并通过事先用α-真菌毒素进行了抑制。荧光α-毒素在酶处理过的肌肉的终板中显示出相似的荧光模式。因此，暂时将荧光探针的突触后定位鉴定为在结合乙酰胆碱受体位点时产生胆碱分解作用的一种。观察到强烈的突触前荧光，并且不会被微摩尔浓度的α-邦加毒素，d-微管尿素，hemicholinium或胆碱酯酶抑制剂改变。在酶处理过的肌肉中观察到了终板区域的微弱可逆染色，并通过事先用α-真菌毒素进行了抑制。荧光α-毒素在酶处理过的肌肉的终板中显示出相似的荧光模式。因此，暂时将荧光探针的突触后定位鉴定为在结合乙酰胆碱受体位点时产生胆碱分解作用的一种。在酶处理过的肌肉中观察到了终板区域的微弱可逆染色，并通过事先用α-真菌毒素进行了抑制。荧光α-毒素在酶处理过的肌肉的终板中显示出相似的荧光模式。因此，暂时将荧光探针的突触后定位鉴定为在结合乙酰胆碱受体位点时产生胆碱分解作用的一种。在酶处理过的肌肉中观察到了终板区域的微弱可逆染色，并通过事先用α-真菌毒素进行了抑制。荧光α-毒素在酶处理过的肌肉的终板中显示出相似的荧光模式。因此，暂时将荧光探针的突触后定位鉴定为在结合乙酰胆碱受体位点时产生胆碱分解作用的一种。