| Abstrakt: |
Effect of TRH on hypothermia,sleep and motor activity induced by chloral hydrate(CH),ketamine(KT),thiamilal sodium(TH), haloperidol(HA) and droperidol(DR) were investigated in mice. The peak responses occurred 15min following TRH injection (5,10,20 and 40mg/kg i.p.),each response being dependent on the dosage. TRH(5,10,20 and 40mg/kg i.p.) was administered to mice just after CH(400mg/kg i.p.),KT(15Omg/kg i.p.),TH (80mg/kg i.p.),HA and DR(2.5mg/kg i.p.),and within 15 to 30 min after TRH,a significant reduction of hypothermia was yielded. TRH(20mg/kg i.p.) reduced motor activity by CH(30 0 mg/kg i.p.),KT(125mg/kg i.p.),TH(4omg/kg i.p.). TRH(5 and 10 mg/kg i.p.) antagonized the sleep induced by CH(400mg/kg i.p.),KT(150mg/kg i.p.),TH(80mg/kg i.p.),but TRH(10mg/kg) significantly increased sleeping time induced by TH(80mg/kg). The results presented show that TRH antagonized hypothermia, sleep and motor activity produced by CH,KT,T.E.,HA and DR. The mechanism of CH,KT and TH antagonism by TRH is uncertain. TRH may exert effects on the central nervous system that are independent of pituitary-thyroid action,and rise of cyclic AMP may be also the mechanism by which TRH antagonized hypothermia,sleep and motor activity produced by CH, KT and TH. |
