Malinowska B, Göthert M, Godlewski G, Wróbel B, Bönisch H, Buczko W
Zaklad Farmakodynamiki Akademia Medyczna, Bialystok, Poland.
Eur J Pharmacol. 1995 May 26;293(1):71-6. doi: 10.1016/0926-6917(95)90020-9.
The influence of ethanol (0.5, 1.0 and 2.0 g/kg i.p.) on the Bezold-Jarisch reflex in urethane-anaesthetized rats was studied. 5-Hydroxytryptamine (serotonin; 5-HT; 1, 3, 10 and 30 micrograms/kg i.v.) and capsaicin (1, 3 and 10 micrograms/kg i.v.) reflexly decreased heart rate in a dose-dependent manner. The 5-HT3 receptor antagonist ondansetron 10 micrograms/kg i.v. abolished the 5-HT- but not the capsaicin-stimulated bradycardia, indicating that 5-HT and capsaicin acted via different trigger mechanisms (5-HT3 receptor-dependent and -independent, respectively). Ethanol at 1.0 and 2.0 g/kg i.p. inhibited in a dose-dependent manner (by 20-45%) the 5-HT- but not the capsaicin-stimulated decrease in heart rate. Our results demonstrate that the inhibitory effect of ethanol on the 5-HT3 receptor-mediated Bezold-Jarisch reflex may be related to the direct effect of ethanol on 5-HT3 receptors on sensory vagal nerves in the heart.
研究了乙醇(腹腔注射0.5、1.0和2.0 g/kg)对氨基甲酸乙酯麻醉大鼠贝佐尔德-雅里什反射的影响。5-羟色胺(血清素;5-HT;静脉注射1、3、10和30微克/千克)和辣椒素(静脉注射1、3和10微克/千克)以剂量依赖方式反射性降低心率。5-HT3受体拮抗剂昂丹司琼10微克/千克静脉注射可消除5-HT刺激的心动过缓,但不能消除辣椒素刺激的心动过缓,表明5-HT和辣椒素通过不同的触发机制起作用(分别为5-HT3受体依赖性和非依赖性)。腹腔注射1.0和2.0 g/kg乙醇以剂量依赖方式(20%-45%)抑制5-HT刺激的心率降低,但不抑制辣椒素刺激的心率降低。我们的结果表明,乙醇对5-HT3受体介导的贝佐尔德-雅里什反射的抑制作用可能与乙醇对心脏感觉迷走神经上5-HT3受体的直接作用有关。