Nicotine modulates nitric oxide in rat brain.
Nicotine exerts its central actions by regulating cationic fluxes through nicotinic acetylcholine receptors (nAChRs). By this effect, the drug likely also modifies events occurring beyond the nAChR, including the regulation of nitric oxide (NO) synthesis. The present study was undertaken to assess the effects of acute and chronic nicotine administration (0.4 mg/kg, s.c.) on levels of NO(-)(2)+NO(-)(3), stable metabolites of NO, in brain regions of male and female rats. Nicotine increased levels of the metabolites, and therefore presumably of NO, with sex differences in the degree of stimulation, the brain regions affected, and the variance between the effects of acute and chronic administration. Prior inhibition of NO synthase eliminated the effect of nicotine in all regions studied. While nicotine appeared to increase NO indirectly via glutamate receptors in the cortex and hippocampus, this was not true of the corpus striatum, where blocking NMDA-type glutamate receptors with MK-801 had no effect. The findings support the view that NO is likely involved in some of the central effects of nicotine.
Pogun
S
S
Ege University Center for Brain Research and TUBITAK Basic Neuroscience Research Unit, 35100, Izmir, Turkey. pogun@med.ege.edu.tr
Demirgoren
S
S
Taskiran
D
D
Kanit
L
L
Yilmaz
O
O
Koylu
E O
EO
Balkan
B
B
London
E D
ED
D000704:Analysis of Variance; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005260:Female; D005731:Ganglionic Stimulants / Q000008:administration & dosage / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D007191:Indazoles / Q000494:pharmacology; D008297:Male; D009538:Nicotine / Q000008:administration & dosage / Q000494:pharmacology*; D009566:Nitrates / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism; D019335:Nitroarginine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012727:Sex Characteristics; D013997:Time Factors
D004791:Enzyme Inhibitors; D018691:Excitatory Amino Acid Antagonists; D005731:Ganglionic Stimulants; D007191:Indazoles; D009566:Nitrates; D009573:Nitrites; D019335:Nitroarginine; D009569:Nitric Oxide; D016291:Dizocilpine Maleate; D009538:Nicotine; C080122:7-nitroindazole