A microdialysis study of the effects of the nicotinic agonist RJR-2403 on cortical release of acetylcholine and biogenic amines.
Transcortical dialysis was employed to investigate the effects of subcutaneous (s.c.) injections of RJR-2403 (1.2-7.2 mumol/kg) on extracellular levels of acetylcholine (ACh), norepinephrine (NE), dopamine (DA), and serotonin (5-HT) in rat. Systemic administration of RJR-2403 produced a 90% increase of cortical extracellular ACh levels that persisted for up to 90 minutes after injection. Norepinephrine and DA release were increased 124% and 131% above basal values, respectively. Serotonin (5-HT) levels in the dialysate were also significantly elevated by RJR-2403 (3.6 mumol/kg, s.c.) 70% above baseline at 90 minutes post-injection. Comparison of these responses to those of (-)nicotine from a previous study reveals little difference between the two compounds in their ability to influence cortical neurotransmitter release following systemic administration.
Summers
K L
KL
Department of Pharmacology, Southern Illinois University School of Medicine, Springfield 62794-1222, USA.
Lippiello
P
P
Giacobini
E
E
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001679:Biogenic Amines / Q000378:metabolism*; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D008297:Male; D017551:Microdialysis; D009538:Nicotine / Q000031:analogs & derivatives* / Q000494:pharmacology; D018722:Nicotinic Agonists / Q000494:pharmacology*; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism
D001679:Biogenic Amines; D018722:Nicotinic Agonists; D012701:Serotonin; C012419:metanicotine; D009538:Nicotine; D000109:Acetylcholine; D004298:Dopamine; D009638:Norepinephrine