Grassi F, Monaco L, Eusebi F
Istituto di Istologia ed Embriologia generale, University of Rome, La Sapienza, Italy.
Biochem Biophys Res Commun. 1987 Sep 30;147(3):1000-7. doi: 10.1016/s0006-291x(87)80169-9.
Rat myotubes exposed to forskolin were studied by patch-clamp technique in cell-attached single channel recording configuration. Channel open time and opening frequency of the main class of acetylcholine receptor- (AChR-) channels (accounting for more than 90% of all unitary events) decreased in the presence of forskolin (20-100 microM). The forskolin-induced action on the AChR function fully developed with a delay of 30-60 minutes from the peak of cytosolic cyclic AMP (cAMPi) concentration. Both cAMP (1 mM), applied intracellularly for 10 min, and dibutyryl cAMP (0.5 mM), applied extracellularly for 90 min, did not accelerate the rate of desensitization of myotubes studied in whole-cell patch-clamp recording configuration. It was concluded that the action of forskolin on AChR-channel function of rat myotubes could be not associated with the cAMPi-dependent phosphorylation of AChR.
采用膜片钳技术的细胞贴附式单通道记录模式，对暴露于福斯高林的大鼠肌管进行了研究。在福斯高林（20 - 100微摩尔）存在的情况下，主要类型的乙酰胆碱受体（AChR）通道（占所有单位事件的90%以上）的通道开放时间和开放频率降低。福斯高林对AChR功能的诱导作用在胞质环磷酸腺苷（cAMPi）浓度达到峰值后30 - 60分钟出现延迟才完全显现。在全细胞膜片钳记录模式下，细胞内施加10分钟的1毫摩尔cAMP和细胞外施加90分钟的0.5毫摩尔二丁酰cAMP，均未加速所研究肌管的脱敏速率。得出的结论是，福斯高林对大鼠肌管AChR通道功能的作用可能与AChR的cAMPi依赖性磷酸化无关。
