Van Hooft J A, Vijverberg H P
Research Institute of Toxicology, Utrecht University, The Netherlands.
Recept Channels. 1995;3(1):7-12.
Single 5-HT3 receptor-gated ion channels were recorded in cell-attached and excised membrane patches of mouse N1E-115 neuroblastoma cells. In cell-attached patches 5-HT3 receptor-gated ion channels show distinct conductance levels of 27, 18, 11 and 6 pS. Patch excision, buffering of intracellular Ca2+ by BAPTA and inhibition of protein kinase activity by staurosporine increase the probability of occurrence of the 6 pS level and decrease that of the 27 pS level. Conversely, patch cramming and stimulation of protein kinase activity by the phorbol ester PMA enhance the probability of occurrence of the 27 pS level and decrease that of low conductance levels. We conclude that phosphorylation controls the conductance of 5-HT3 receptor ligand-gated ion channels. Control of channel conductance may prove an additional mechanism in the modulation of synaptic efficacy.
在小鼠N1E - 115神经母细胞瘤细胞的细胞贴附式和切除式膜片中记录到了单个5 - 羟色胺3（5-HT3）受体门控离子通道。在细胞贴附式膜片中，5-HT3受体门控离子通道呈现出27、18、11和6皮西门子的不同电导水平。膜片切除、用1,2 -双（2 -氨基苯氧基）乙烷-N,N,N',N'-四乙酸（BAPTA）缓冲细胞内钙离子以及用星形孢菌素抑制蛋白激酶活性会增加6皮西门子水平出现的概率，并降低27皮西门子水平出现的概率。相反，膜片填充以及用佛波酯PMA刺激蛋白激酶活性会提高27皮西门子水平出现的概率，并降低低电导水平出现的概率。我们得出结论，磷酸化作用控制着5-HT3受体配体门控离子通道的电导。通道电导的控制可能是调节突触效能的一种额外机制。
