Nicotine-induced protection of cultured cortical neurons against N-methyl-D-aspartate receptor-mediated glutamate cytotoxicity.
The effects of nicotine on glutamate-induced cytotoxicity were examined using primary cultures of rat cortical neurons. The cell viability was significantly reduced when cultures were briefly exposed to glutamate or N-methyl-D-aspartate (NMDA) then incubated with normal medium for 1 h. A 1-h exposure of the cultures to kainate or alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) reduced cell viability. Incubating cultures with nicotine for 1-24 h protected cortical neurons against glutamate cytotoxicity. Maximum protection against glutamate cytotoxicity was induced with a 2-h nicotine incubation. Exposure to nicotine for up to 2 h did not affect cell viability by itself although cell viability was reduced in a time-dependent manner when the exposure exceeded 4 h. Neuroprotection by nicotine was dependent on both the concentration and incubation period. Nicotine reduced the NMDA cytotoxicity but did not attenuate that of kainate and AMPA. The neuroprotective effects of nicotine against glutamate cytotoxicity were antagonized by mecamylamine and hexamethonium but not by atropine. These results indicate that nicotinic receptor stimulation induces neuroprotection against glutamate cytotoxicity mediated by NMDA receptors.
Akaike
A
A
Department of Neuropharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, Japan.
Tamura
Y
Y
Yokota
T
T
Shimohama
S
S
Kimura
J
J
D000818:Animals; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000187:drug effects*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D005971:Glutamates / Q000633:toxicity*; D018698:Glutamic Acid; D009410:Nerve Degeneration / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects*; D009538:Nicotine / Q000494:pharmacology*; D010275:Parasympathetic Nervous System / Q000166:cytology / Q000187:drug effects; D010277:Parasympathomimetics / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000187:drug effects*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
D005971:Glutamates; D010277:Parasympathomimetics; D010879:Piperazines; D016194:Receptors, N-Methyl-D-Aspartate; D018698:Glutamic Acid; D016291:Dizocilpine Maleate; D009538:Nicotine; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; C050592:3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid