Back to Search
Start Over
Nicotinic acetylcholine receptor (nACh-R) agonist-induced changes in brain monoamine turnover in mice.
- Source :
-
Psychopharmacology . 1997, Vol. 129 Issue 3, p225. 8p. - Publication Year :
- 1997
-
Abstract
- Abstract The aim of the present study was to evaluate the effects of nicotinic acetylcholine receptor (nACh-R) agonists such as (-)-nicotine and related compounds on brain monoamine turnover. A single administration of (-)-nicotine (0.04, 0.2, 1.0, and 5.0 mg/kg SC) increased both noradrenaline (NA) and dopamine (DA) turnover in a dose-dependent manner, and the maximum effects were achieved 30 min after treatment with (-)-nicotine (1.0 mg/kg). The effect of (-)-nicotine on serotonin (5-HT) turnover was complicated; 5-HT turnover was increased at a low dose of (-)-nicotine (0.04 mg/kg) but decreased at a high dose (1.0 mg/kg). The (-)-nicotine (1.0 mg/kg)-induced changes in monoamine turnover were blocked by pretreatment with the centrally acting nACh-R channel blocker mecamylamine (2.0 mg/kg IP) but not by hexamethonium (2.0 mg/kg IP). These findings indicate that systemically administered (-)-nicotine can enhance brain NA and DA turnover and affect 5-HT turnover, both of which are mediated by central nACh-R. The changes in the monoamine turnover induced by (+/-)-anabasine were similar to those induced by (-)-nicotine, while (-)-lobeline and (-)-cytisine had little effect, and 1,1-dimethyl-4-phenyl-piperazinium (DMPP) increased NA and 5-HT turnover but not DA turnover at all doses tested. (S)-3-Methyl-5-(1-methyl2-pyrrolidinyl)-isoxazole (ABT-418), a selective neuronal nACh-R agonist, increased NA, DA and 5-HT turnover, but had a weaker effect on DA turnover than NA and 5-HT turnover. In addition, 9-amino-1,2,3,4-tetrahydroacridine (THA), an acetylcholine esterase inhibitor, also increased monoamine turnover in the brain. Pretreatment with mecamylamine completely blocked the THA-induced increase in NA and 5-HT turnover, but not in DA turnover, suggesting that the nACh-R system is involved in the THA-induced increase in brain NA and 5-HT turnover. On the other hand, (-)-cytisine, a partial agonist for the beta 2 subunit containing nACh-R, completely inhibited the nA [ABSTRACT FROM AUTHOR]
- Subjects :
- *CHOLINERGIC receptors
*NORADRENALINE
*DOPAMINE
*SEROTONIN
Subjects
Details
- Language :
- English
- ISSN :
- 00333158
- Volume :
- 129
- Issue :
- 3
- Database :
- Academic Search Index
- Journal :
- Psychopharmacology
- Publication Type :
- Academic Journal
- Accession number :
- 4693758
- Full Text :
- https://doi.org/10.1007/s002130050184