纳洛酮对急性低氧大鼠左心室内压的影响

Effect of Naloxone on Left Ventricular Pressure During Acute Hypoxia in Rats

实验在雄性成年SD大鼠上进行,麻醉后气管插管,用人工呼吸机经气袋自发吸入9%低氧气体,并记录左心室内压。结果:(1)急性低氧时左心室内压显著降低,而低氧后静脉注射不同剂量的纳洛酮(1mg/kg/mL、5mg/kg/mL)则可以部分逆转急性低氧时左心室内压的下降。(2)第四脑室注射2μL纳洛酮(1μg/μL)也可以部分逆转急性低氧时体内内啡肽系统可能参与急性低氧时的左心室内压的下降,而内啡肽拮抗剂纳洛酮则部分对抗急性低氧时左心室内压的下降。

Experiments were performed on male SD rats. All the animals were anesthetized with a mixture of urethane (700mg/kg) and α - chloralose(35mg/kg). The left ventricular pressure decreased significantly during acute 9 percent hypoxia, however, intravenous injection naloxone at different doses can antagonize the effect of hypoxia on left ventricrular pressure,at least in part. Microinjection of naloxone to the fourth ventriclar of brain has the same effect on the left ventricular pressure during acute hypoxia. These results indicate that endor-phin maybe play a important role during acute hypoxia,Acute hypoxia induced decrement of left ventricular pressure could be suppressed by administration of endorphin antagonist naloxone.