|
|
|
|
Vol. 55, Issue 1, 58-66, January 1999
4
2 Receptors
Stably Expressed in HEK293 Cells
Department of Anesthesiology, Washington University School of
Medicine, St. Louis, Missouri
HEK293 cells were stably transfected with rat neuronal nicotinic
4
and
2 subunits. Binding of tritiated cytisine and nicotine to cell
homogenates revealed the presence of a single class of high-affinity
sites (dissociation constants 0.1 nM and 0.4 nM, respectively).
Activation of nicotinic receptors was studied using whole-cell patch
clamp methods, and acetylcholine, nicotine, dimethylphenylpiperazinium, and cytisine all produced a conductance increase. Responses
desensitized to prolonged applications, at both positive and negative
membrane potentials. The conductance was strongly rectifying, and
outward currents were essentially absent. Responses were maximal at
about 2 mM external calcium ion concentration and were reduced by about one-half at either nominally 0 or 10 mM external calcium.
Di-hydro-
-erythroidine blocked physiological responses to
acetylcholine and nicotine (IC50, 2.5 nM), and reduced
cytisine binding in a competitive manner (Ki
20 nM). Physostigmine enhanced the response to low concentrations of
acetylcholine or nicotine. The anesthetic steroid (+)-3
-hydroxy-5
-androstane-17
-carbonitrile blocked responses to acetylcholine (IC50, 1.3 µM), but had no effect on
cytisine binding at a concentration of 30 µM. The binding properties
of the receptors are those expected for rat neuronal nicotinic
receptors composed of
4 and
2 subunits. The pharmacological
properties indicate that the responsiveness of the receptors may be
allosterically enhanced or inhibited.
This article has been cited by other articles:
![]() |
W. Li, X. Jin, D. F. Covey, and J. H. Steinbach Neuroactive Steroids and Human Recombinant {rho}1 GABA Receptors J. Pharmacol. Exp. Ther., October 1, 2007; 323(1): 236 - 247. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Kishi and J. H. Steinbach Role of the Agonist Binding Site in Up-Regulation of Neuronal Nicotinic {alpha}4beta2 Receptors Mol. Pharmacol., December 1, 2006; 70(6): 2037 - 2044. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. A. Briggs, E. J. Gubbins, M. J. Marks, C. B. Putman, R. Thimmapaya, M. D. Meyer, and C. S. Surowy Untranslated Region-Dependent Exclusive Expression of High-Sensitivity Subforms of {alpha}4beta2 and {alpha}3beta2 Nicotinic Acetylcholine Receptors Mol. Pharmacol., July 1, 2006; 70(1): 227 - 240. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. M. Person, K. L. Bills, H. Liu, S. K. Botting, J. Lindstrom, and G. B. Wells Extracellular Domain Nicotinic Acetylcholine Receptors Formed by {alpha}4 and {beta}2 Subunits J. Biol. Chem., December 2, 2005; 280(48): 39990 - 40002. [Abstract] [Full Text] [PDF] |
||||
![]() |
J.-Z. Guo, Y. Liu, E. M. Sorenson, and V. A. Chiappinelli Synaptically Released and Exogenous ACh Activates Different Nicotinic Receptors to Enhance Evoked Glutamatergic Transmission in the Lateral Geniculate Nucleus J Neurophysiol, October 1, 2005; 94(4): 2549 - 2560. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. F. Vallejo, B. Buisson, D. Bertrand, and W. N. Green Chronic Nicotine Exposure Upregulates Nicotinic Receptors by a Novel Mechanism J. Neurosci., June 8, 2005; 25(23): 5563 - 5572. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. A. Jensen, I. Mikkelsen, B. Frolund, H. Brauner-Osborne, E. Falch, and P. Krogsgaard-Larsen Carbamoylcholine Homologs: Novel and Potent Agonists at Neuronal Nicotinic Acetylcholine Receptors Mol. Pharmacol., October 1, 2003; 64(4): 865 - 875. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Darbandi-Tonkabon, W. R. Hastings, C.-M. Zeng, G. Akk, B. D. Manion, J. R. Bracamontes, J. H. Steinbach, S. J. Mennerick, D. F. Covey, and A. S. Evers Photoaffinity Labeling with a Neuroactive Steroid Analogue. 6-AZI-PREGNANOLONE LABELS VOLTAGE-DEPENDENT ANION CHANNEL-1 IN RAT BRAIN J. Biol. Chem., April 4, 2003; 278(15): 13196 - 13206. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. E. Nelson, A. Kuryatov, C. H. Choi, Y. Zhou, and J. Lindstrom Alternate Stoichiometries of alpha 4beta 2 Nicotinic Acetylcholine Receptors Mol. Pharmacol., February 1, 2003; 63(2): 332 - 341. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Dobelis, M. J. Marks, P. Whiteaker, S. A. Balogh, A. C. Collins, and J. A. Stitzel A Polymorphism in the Mouse Neuronal alpha 4 Nicotinic Receptor Subunit Results in An Alteration in Receptor Function Mol. Pharmacol., August 1, 2002; 62(2): 334 - 342. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Dourado and P. B. Sargent Properties of Nicotinic Receptors Underlying Renshaw Cell Excitation by alpha -Motor Neurons in Neonatal Rat Spinal Cord J Neurophysiol, June 1, 2002; 87(6): 3117 - 3125. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Paradiso, J. Zhang, and J. H. Steinbach The C Terminus of the Human Nicotinic {alpha}4{beta}2 Receptor Forms a Binding Site Required for Potentiation by an Estrogenic Steroid J. Neurosci., September 1, 2001; 21(17): 6561 - 6568. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Buisson and D. Bertrand Chronic Exposure to Nicotine Upregulates the Human {alpha}4{beta}2 Nicotinic Acetylcholine Receptor Function J. Neurosci., March 15, 2001; 21(6): 1819 - 1829. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Paradiso, K. Sabey, A. S. Evers, C. F. Zorumski, D. F. Covey, and J. H. Steinbach Steroid Inhibition of Rat Neuronal Nicotinic alpha 4beta 2 Receptors Expressed in HEK 293 Cells Mol. Pharmacol., August 1, 2000; 58(2): 341 - 351. [Abstract] [Full Text] |
||||