第四脑室注射吗啡对应激性高血粘度与血压升高的影响

实验用Wistar大鼠99只,雄性250g左右,随机分三组:对照组、悬吊加束缚组、悬吊一束缚加电针组。结果:(1)清醒大鼠束缚加悬吊可引起应激性高血粘度和血压升高,切断双侧颈迷走神经后上述现象仍存在。静脉注射心得安(0.3mg/ml)或酚妥拉明(0.3 mg/ml)对正常大鼠血压、血粘度影响不大,但对应激性血压升高均有抑制作用。静脉注射心得安还可降低应激性高血粘度。(2)电针大鼠右后肢对应激性高血粘度和血压升高有抑制作用。(3)第四脑室内注射吗啡(10μg/10 μl)15或30min后可降低应激性高血粘度和血压升高,注入等量生理盐水无变化。若在第四脑室注射纳洛酮 (10μg/10μl)则可部分阻断电针右后肢对悬吊-束缚诱发的高血粘度和血压升高的抑制作用。结果提示:悬吊-束缚大鼠可能兴奋交感神经传出系统经激活β受体诱发应激性高血粘度阻断α或β受体可降低应激性血压升高。脑内阿片肽可抑制应激性高血粘度和血压升高,脑内河片肽受体的激活可参与电针后肢对应激性高血粘度和血压升高的抑制作用。

INHIBITORY EFFECT OF INTRAVENTRICULAR ADMINISTRATION OF MORPHINE ON THE HYPERVISCOSITY AND ELEVATION OF BLOOD PRESSURE INDUCED BY STRESS IN THE RAT

Experiments were performed on 99 Wistar rats. It was found that hyperviscosityand elevation of blood pressure (BP) could be induced by hanging and restraining con-scious rats with their four limbs tied on a frame. These effects were unaffected by bilat-eral vagotomy. By intravenous injection of propranolol or phentolamine, elevation ofBP could be reduced, while stress--induced hyperviscosity could only be reduced by pro-pranolol (i. v. ). Stress--induced hyperviscosity and elevation of BP could be inhibitedby electroacupuncture applied to the right hing leg or microinjection of morphine into4th ventricle of the brain. On the other hand, if opiate receptor antagonist naloxone was given into the 4th-ventricle, the stress--induced hyperviscosity and elevation of BP could no longer be inhibited by electroacupuncture. It is suggested that the hyperviscosity and elevation of BP induced by hanging andrestraining are mediated by excitutory cardiovascular sympethetic outflow with the re-sult of activation of adrenoreceptors. Activation of the opiate receptors in the hindbrainmay be responsible for decrease in stress--induced hyperviscosity and elevation of BPand for the inhibitory effect of electroacupuncture of the right hind leg on stress--in--duced hyperviscosity and elevation of BP.