Premium
Native Nicotinic Acetylcholine Receptors in Human Imr32 Neuroblastoma Cells: Functional, Immunological and Pharmacological Properties
Author(s) -
Gotti C.,
Briscini L.,
Verderio C.,
Oortgiesen M.,
Balestra B.,
Clementi F.
Publication year - 1995
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.1995.tb00630.x
Subject(s) - acetylcholine receptor , receptor , g alpha subunit , nicotinic agonist , polyclonal antibodies , alpha (finance) , protein subunit , cys loop receptors , biology , intracellular , extracellular , microbiology and biotechnology , nicotinic acetylcholine receptor , pharmacology , biophysics , biochemistry , antibody , medicine , immunology , gene , construct validity , nursing , patient satisfaction
IMR32 cells express two classes of surface nicotinic receptors: those labelled with high affinity by [ 125 I]neuronal toxin, and those labelled by [ 125 Iα‐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 α‐bungarotoxin. In IMR32 cells, nicotine induces an increase in the intracellular level of free Ca 2+ . This increase, which is also completely blocked by d‐tubocurarine and only partially blocked by α‐bungarotoxin and Cd 2+ , is due to extracellular calcium influx through both the nicotinic receptors and the voltage‐activated Ca 2+ channels. By using subunit‐specific polyclonal antibodies, we have demonstrated that the α‐bungarotoxin receptors contain the α7 subunit, but none of the other subunits whose transcripts are present in IMR32 cells. The pharmacological profile of these human α7‐containing α‐bungarotoxin receptors is similar to that observed in the native chick α7 receptor, but there are also some species‐specific differences.