Vallejo M, Lightman S L
Life Sci. 1986 May 19;38(20):1859-66. doi: 10.1016/0024-3205(86)90141-4.
The haemodynamic effects of intracerebroventricular (i.c.v.) administration of neuropeptide Y (NPY) in urethane-anaesthetized rats were studied. In Sprague-Dawley rats, NPY increased both blood pressure and heart rate in a dose-dependent manner. This response was unaffected by removal of the adrenal medullae or pretreatment with a specific vasopressin antagonist (180 ng/kg i.v.), but was abolished by phenoxybenzamine (1mg/kg i.v.). After pretreatment with propranolol (1mg/kg i.v.), the tachycardia was inhibited and the pressor response was of shorter duration than in controls. In 6-hydroxydopamine treated rats (two doses of 250 micrograms i.c.v., three days apart), NPY still elicited a pressor response and tachycardia, which were significantly higher than controls 15 minutes after the injection. Plasma levels of vasopressin were not altered by i.c.v. administration of NPY. However, in Brattleboro rats the peptide had no haemodynamic effects. Our results suggest that activation of sympathetic nervous system but not release of vasopressin or adrenal catecholamines into the bloodstream mediates the cardiovascular response to NPY. Central vasopressin pathways however may be involved.
研究了在乌拉坦麻醉的大鼠中脑室内（i.c.v.）注射神经肽Y（NPY）的血流动力学效应。在斯普拉格-道利大鼠中，NPY以剂量依赖的方式升高血压和心率。这种反应不受肾上腺髓质切除或用特异性血管加压素拮抗剂（180 ng/kg静脉注射）预处理的影响，但被酚苄明（1mg/kg静脉注射）消除。用普萘洛尔（1mg/kg静脉注射）预处理后，心动过速受到抑制，升压反应的持续时间比对照组短。在6-羟基多巴胺处理的大鼠（间隔三天脑室内注射两剂250微克）中，NPY仍引起升压反应和心动过速，注射后15分钟时显著高于对照组。脑室内注射NPY未改变血管加压素的血浆水平。然而，在布拉特洛维大鼠中，该肽没有血流动力学效应。我们的结果表明，交感神经系统的激活而非血管加压素或肾上腺儿茶酚胺释放到血流中介导了对NPY的心血管反应。然而，中枢血管加压素途径可能参与其中。
