The effects of rubidium, caesium and quinine on 5-HT-mediated behaviour in rat and mouse--2. Caesium.
Rats and mice were given either CsCl (3 mmol/kg, s.c.) or saline (as control), twice daily for 3 days. The administration of tranylcypromine (TCP) (15 mg/kg, i.p.) to rats pretreated with CsCl produced the 5-HT behavioural syndrome. Pretreatment with CsCl also enhanced the syndrome induced by p-chloroamphetamine (3 mg/kg, i.p.) or by TCP (15 mg/kg, i.p.) plus L-tryptophan (50 mg/kg, i.p.). p-Chlorophenylalanine (300 mg/kg, i.p., daily on 2 consecutive days) or (-)-propranolol (20 mg/kg, i.p.), pindolol (4 mg/kg, i.p.) and ritanserin (0.4 mg/kg, s.c.), all prevented the behavioural syndrome induced by CsCl and TCP in rats. Pretreatment of rats with CsCl potentiated the 5-HT syndrome, elicited by the 5-HT agonists, 8-OH-DPAT (0.5 mg/kg, s.c.), 5-MeODMT (2 mg/kg, s.c.) and quipazine (25 mg/kg, i.p.). Pretreatment with CsCl potentiated the 5-HT2-mediated head-twitches in the mouse but had no effects on hypothermia in the mouse induced by 8-OH-DPAT (0.5 mg/kg, s.c.). The rate of synthesis of 5-HT in the whole brain (excluding cerebellum) was enhanced by pretreatment with CsCl. The enhancement of 5-HT neuronal function by caesium may be related to its ability to block K(+)-channels in neuronal membranes.
Wang
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MRC Unit, Radcliffe Infirmary, Oxford, U.K.
Grahame-Smith
D G
DG
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001831:Body Temperature / Q000187:drug effects; D002586:Cesium / Q000494:pharmacology*; D002712:Chlorides; D004357:Drug Synergism; D051379:Mice; D015221:Potassium Channels / Q000187:drug effects; D051381:Rats; D011985:Receptors, Serotonin / Q000187:drug effects; D012701:Serotonin / Q000096:biosynthesis / Q000502:physiology*; D014191:Tranylcypromine / Q000494:pharmacology; D014364:Tryptophan / Q000494:pharmacology; D010133:p-Chloroamphetamine / Q000494:pharmacology
D002712:Chlorides; D015221:Potassium Channels; D011985:Receptors, Serotonin; D002586:Cesium; D012701:Serotonin; D014191:Tranylcypromine; D010133:p-Chloroamphetamine; D014364:Tryptophan; C028019:cesium chloride