Bot G, Chahl L A
Neuropharmacology Laboratory, Faculty of Medicine, University of Newcastle, N.S.W. Australia.
Eur J Pharmacol. 1993 Jan 26;231(1):53-60. doi: 10.1016/0014-2999(93)90683-9.
The effects of pretreatment with pertussis toxin (PTX) on the sedative effect of morphine administered i.c.v. (200 nmol), and on the locomotor and behavioural activation precipitated by naloxone (15 mg/kg s.c.) following treatment with a single dose of morphine (i.c.v., 200 nmol), were investigated in guinea-pigs. Responses to i.c.v. administration of substance P (50 nmol), quinpirole (200 nmol), U50,488H (100 nmol) and carbachol (2 nmol) following PTX pretreatment were also investigated. Following PTX pretreatment, morphine induced mild agitation and the onset of sedation was delayed. Pretreatment with PTX also attenuated the locomotor and some components of behavioural activation induced by substance P, U50,488H, quinpirole and naloxone-precipitated morphine withdrawal, but failed to attenuate the effects induced by carbachol. These results suggest the involvement of PTX-sensitive G-protein-mediated mechanisms in the sedative effect of morphine in guinea-pigs and in the central stimulating actions of acute morphine withdrawal, U50,488H, substance P, and quinpirole.
研究了百日咳毒素（PTX）预处理对脑室内注射吗啡（200 nmol）镇静作用的影响，以及对单剂量吗啡（脑室内注射，200 nmol）处理后纳洛酮（15 mg/kg皮下注射）引发的运动和行为激活的影响。还研究了PTX预处理后对脑室内注射P物质（50 nmol）、喹吡罗（200 nmol）、U50,488H（100 nmol）和卡巴胆碱（2 nmol）的反应。PTX预处理后，吗啡引起轻度躁动，镇静起效延迟。PTX预处理还减弱了P物质、U50,488H、喹吡罗和纳洛酮诱发的吗啡戒断所诱导的运动和某些行为激活成分，但未能减弱卡巴胆碱所诱导的效应。这些结果表明，PTX敏感的G蛋白介导机制参与了吗啡对豚鼠的镇静作用以及急性吗啡戒断、U50,488H、P物质和喹吡罗的中枢刺激作用。
