Evidence exists that multiple subtypes of neuronal nAChRs are present throughout the nervous system, with differing pharmacology and regulation. Chromaffin cells from the adrenal medulla express neuronal nAChRs. Although these nAChRs are the principal receptors mediating release of catecholamines from the adrenal gland, little information is available on the molecular composition and regulation of these physiologically important receptors. These proposed studies address the hypotheses that heterogeneous populations of nAChRs are expressed in adrenal chromaffin cells and that the cytoskeletal network plays an important role in regulating nAChR activity. In these studies nAChR subtypes mediating secretion will be characterized. Alterations in subunit composition will be directly correlated with changes in agonist/antagonist sensitivity and secretion.
The specific aims of the proposed research are 1) to identify the nAChR genes expressed in adrenal chromaffin cells and isolate full-length cDNAs for the expressed genes, 2) to determine which nAChRs subtypes are expressed and 3) to determine the functional contribution of the various nAChR subunits/subtypes and investigate their regulation. Northern analysis, PCR techniques and cDNA cloning will be used to determine which nAChR genes are expressed. Binding experiments, immunopurification and affinity chromatography will be used to characterize nAChR subtypes, and antisense oligonucleotides and specific nAChR antibodies will be used to probe the functional role of specific adrenal nAChR subunit gene products and specific nAChR subtypes in adrenal secretion. These studies should contribute significantly to our current knowledge of adrenal nAChRs and may also contribute to our basic understanding of neuronal nAChRs and their regulation.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Research Project (R01)
Project #
5R01DA010569-02
Application #
2872085
Study Section
Human Development Research Subcommittee (NIDA)
Program Officer
Colvis, Christine
Project Start
1998-03-15
Project End
2002-01-31
Budget Start
1999-02-01
Budget End
2000-01-31
Support Year
2
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Ohio State University
Department
Type
Schools of Pharmacy
DUNS #
098987217
City
Columbus
State
OH
Country
United States
Zip Code
43210
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McKay, Dennis B; Chang, Cheng; Gonzalez-Cestari, Tatiana F et al. (2007) Analogs of methyllycaconitine as novel noncompetitive inhibitors of nicotinic receptors: pharmacological characterization, computational modeling, and pharmacophore development. Mol Pharmacol 71:1288-97
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Free, R Benjamin; McKay, Susan B; Gottlieb, Paul D et al. (2005) Expression of native alpha3beta4* neuronal nicotinic receptors: binding and functional studies investigating turnover of surface and intracellular receptor populations. Mol Pharmacol 67:2040-8
Free, R Benjamin; McKay, Dennis B (2003) Surface and intracellular nicotinic receptors expressed in intact adrenal chromaffin cells: direct measurements using [3H]epibatidine. Brain Res 974:60-9
Free, R Benjamin; von Fischer, Nathaniel D; Boyd, R Thomas et al. (2003) Pharmacological characterization of recombinant bovine alpha3beta4 neuronal nicotinic receptors stably expressed in HEK 293 cells. Neurosci Lett 343:180-4
McKay, Dennis B; Free, R Benjamin; Kaser, Daniel J et al. (2002) Characterization of [(3)H]epibatidine binding to nicotinic receptors from bovine adrenal medulla. Ann N Y Acad Sci 971:162-4
Bryant, Darrell L; Free, R Benjamin; Thomasy, Sara M et al. (2002) Structure-activity studies with ring E analogues of methyllycaconitine on bovine adrenal alpha3beta4* nicotinic receptors. Neurosci Res 42:57-63
Free, R Benjamin; Bryant, Darrell L; McKay, Susan B et al. (2002) [3H]Epibatidine binding to bovine adrenal medulla: evidence for alpha3beta4* nicotinic receptors. Neurosci Lett 318:98-102
Free, R Benjamin; McKay, Susan B; Boyd, R Thomas et al. (2002) Evidence for constitutive expression of bovine adrenal a3beta4* nicotinic acetylcholine receptors. Ann N Y Acad Sci 971:145-7

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