NATIVE NICOTINIC ACETYLCHOLINE-RECEPTORS IN HUMAN IMR32 NEUROBLASTOMA-CELLS - FUNCTIONAL, IMMUNOLOGICAL AND PHARMACOLOGICAL PROPERTIES
NATIVE NICOTINIC ACETYLCHOLINE-RECEPTORS IN HUMAN IMR32 NEUROBLASTOMA-CELLS - FUNCTIONAL, IMMUNOLOGICAL AND PHARMACOLOGICAL PROPERTIES
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DOI：
10.1111/j.1460-9568.1995.tb00630.x
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发表时间：
1995-10-01
影响因子：
3.4
通讯作者：
CLEMENTI, F
中科院分区：
文献类型：
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作者：
GOTTI, C;BRISCINI, L;CLEMENTI, F
IMR32细胞表达两类表面尼古丁受体：那些被[I-125]神经元毒素标记为高亲和力的受体，和那些被[(125)]α -班加罗毒素标记的受体。全细胞膜片钳记录表明，这两类受体都能引起向内电流，这些电流被d-管库尔碱完全阻断，而被α -班加罗毒素部分阻断。在IMR32细胞中，尼古丁诱导细胞内游离Ca2+水平的增加。这种增加是由于细胞外钙通过烟碱受体和电压激活的Ca2+通道流入所致，它也被d-管curarine完全阻断，仅被α -bungarotoxin和Cd2+部分阻断。通过使用亚基特异性多克隆抗体，我们已经证明α -班加罗毒素受体含有α 7亚基，但在IMR32细胞中没有其他亚基的转录本。这些含有α - 7的人类α -班加罗毒素受体的药理学特征与在本地鸡α - 7受体中观察到的相似，但也存在一些物种特异性差异。
IMR32 cells express two classes of surface nicotinic receptors: those labelled with high affinity by [I-125]neuronal toxin, and those labelled by [(125)]alpha-bungarotoxin. Whole-cell patch-clamp recordings indicate that both classes of receptor are able to elicit inward currents that are totally blocked by d-tubocurarine but only partially blocked by alpha-bungarotoxin. In IMR32 cells, nicotine induces an increase in the intracellular level of free Ca2+. This increase, which is also completely blocked by d-tubocurarine and only partially blocked by alpha-bungarotoxin and Cd2+, is due to extracellular calcium influx through both the nicotinic receptors and the voltage-activated Ca2+ channels. By using subunit-specific polyclonal antibodies, we have demonstrated that the alpha-bungarotoxin receptors contain the alpha 7 subunit, but none of the other subunits whose transcripts are present in IMR32 cells. The pharmacological profile of these human alpha 7-containing alpha-bungarotoxin receptors is similar to that observed in the native chick alpha 7 receptor, but there are also some species-specific differences.