Involvement of noradrenergic and 5-hydroxytryptaminergic systems in allylnitrile-induced head twitching.
Allylnitrile induces in rats persistent behavioral abnormalities, including head twitching, following a single administration. We studied the role of 5-hydroxytryptamine (5-HT) and noradrenaline (NA) systems in the brain of rats in inducing and maintaining the head twitching. Allynitrile (1.49 mmol/kg) induced 5-HT system activation in all areas of the brain studied 1-4 days after oral administration, and a reduction in the content of NA in the hippocampus, cortex and hypothalamus 1 day after dosing, in the hippocampus, cortex, hypothalamus and midbrain 2 days after dosing, and in the hypothalamus 4 days after dosing. Allylnitrile induced no change in the content of 5-HT, 5-hydroxyindoleacetic acid (5-HIAA) or NA 7-28 days after dosing. Pretreatment with 5,7-dihydroxytryptamine (5,7-DHT) suppressed the allylnitrile-induced head twitching, and decreased the contents of 5-HT and 5-HIAA in almost all areas of the brain throughout the observation period, as well as the ratio of 5-HIAA/5-HT in the medulla oblongata plus pons from 1 to 30 days after dosing with allylnitrile. No change in NA was observed in any areas of the brain. Pretreatment with N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) increased the head twitching induced by allylnitrile, and decreased the content of NA in all areas of the brain throughout the observation period, without any change in the contents of 5-HT or 5-HIAA or in the ratio of 5-HIAA/5-HT. The present results suggest the involvement of 5-HT and NA systems in allylnitrile-induced head twitching.
Tanii
H
H
Department of Hygiene, School of Medicine, Kanazawa University, Japan.
Huang
J
J
Hashimoto
K
K
D015116:5,7-Dihydroxytryptamine / Q000494:pharmacology; D000818:Animals; D001596:Benzylamines / Q000494:pharmacology; D004409:Dyskinesia, Drug-Induced / Q000209:etiology / Q000503:physiopathology*; D006257:Head; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008297:Male; D009570:Nitriles; D009638:Norepinephrine / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism / Q000502:physiology*
D001596:Benzylamines; D009570:Nitriles; D015116:5,7-Dihydroxytryptamine; D012701:Serotonin; C031103:crotononitrile; C015660:allyl cyanide; D006897:Hydroxyindoleacetic Acid; C012102:DSP 4; D009638:Norepinephrine