大鼠侧脑室内注射[D-Trp^(11)]-神经降压素对心血管反应的影响

In Effect of Intracerebroventricular Injection of [D Trp\+\{11\}] neurotensin on the Cardiova scular Responses in Rats

目的 研究大鼠侧脑室注射（ｉｃｖ）［Ｄ－Ｔｒｐ１１］－神经降压素（［Ｄ－Ｔｒｐ１１ ］－ＮＴ）对心血管活动的影响。方法 将［Ｄ－Ｔｒｐ１１ ］－ＮＴ注入乌拉坦麻醉的雄性ＳＤ大鼠（４０只）侧脑室，观察血压（ＢＰ）和心率（ＨＲ）的变化。结果 ｉｃｖ ［Ｄ－Ｔｒｐ１１］－ＮＴ（１０ μｇ）可引起血压下降和心率减慢；切断大鼠的两侧颈部迷走神经后，再ｉｃｖ［Ｄ－Ｔｒｐ１１］－ＮＴ，所有动物的降压和降心率反应均明显减弱。预先ｉｃｖ［Ｄ－Ｔｒｐ１１］－ＮＴ（２．５ μｇ），可阻断神经降压素（ＮＴ）的中枢降压和降心率反应。结论 ［Ｄ－Ｔｒｐ１１ ］－ＮＴ在一定的剂量范围内具有激动剂的特性；ＮＴ的中枢心血管抑制效应是由脑中的ＮＴ受体介导的。

Objective\ To investigate the effect of [D Trp\+\{11\}] neurotensin ([D Trp\+\{11\}] NT) injected into cerebroventricle on cardiovascular responses in rats. Methods\ Arterial blood pressure(BP) and heart rate (HR) were monitored following injection of [D Trp\+\{11\}] NT into the lateral cerebral ventricle in male SD rats anaesthetized with urethane. Results\ [D Trp\+\{11\}] NT (10 μg) could induce a drop in BP and a decrease of HR. The depressor and bradycardic responses to [D Trp\+\{11\}] NT could markedly weaken after bilateral cervical vagotomy. The central depressor and bradycardic responses to neurotensin (NT) could be blocked with pretreatment of [D Trp\+\{11\}] NT (2.5 μg). Conclusion\ [D Trp\+\{11\}] NT has the dual characteristics of both agonist and antagonist. The central cardiovascular suppressive effect of NT is mediated by the NT receptors in the brain.