The novel roles of the area postrema and NTS in cardiovascular regulation

后区和 NTS 在心血管调节中的新作用

基本信息

批准号：
10672084
负责人：
TAKANO Yukio
金额：
$ 2.11万
依托单位：
Fukuoka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

1. Role of the area postrema in the arterial baroreceptor reflex of ratsIn this project, we examined the synaptic connection to the nucleus tractus solitarius (NTS) from the area postrema (AP). We examined that the effects of glutamate receptor antagonists on the responses of NTS neurons to AP stimulation. The action potentials in the NTS were produced by AP stimulation at 0.2 Hz. These action potentials were blocked by a low Ca^<2+> and a high Mg^<2+> solution or 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) at 10^<-5> M, but not by DL-2-amino-5-phsphonovaleric acid (AP-5) at 10^<-5> M.Judging from the response time, some NTS neurons may be innervated directly by nerve terminals of AP neurons. These results indicate that the excitation by vasopressin of AP neurons mediated V1 receptors is conveyed to NTS by glutamate via NMDA and non-NMDA receptors, or non-NMDA receptors only.2. Role of the area postrema in emesis.The emetic response is a defense mechanism which is extremely complicated. Vomiting is a reflex that integrates the visceral afferent and efferent pathways at the vomiting center, which is considered to be situated in the medulla oblongata. Using immunohistochemical techniques, the presence of substance P-containing nerve fibers involved in emesis in the rats and humans has been demonstrated. We observed the localization of tachykininNK-1 receptors in these areas in an auto radiographic receptor binding study using ^3H-substance P as a binding ligand in ferrets. The emetic response induced by either morphine or copper sulphate was suppressed by the microinjection of NK-1 receptor antagonists, HSP-117 (1.0 μg) and CP-99,994 (7.5 μg), into the AP of ferrets. These results show that the NK-1 receptors in the AP, NTS and the dorsal motor nucleus of the vagus may be involved in the mechanisms of emesis.

1。区域postrema在该项目的Ratsin的动脉压力感受器反射中的作用，我们检查了来自Postrema区域（AP）的突触连接。我们检查了谷氨酸受体拮抗剂对NTS神经元对AP刺激的反应的影响。 NTS中的动作电位是通过0.2 Hz的AP刺激产生的。 These action potentials were blocked by a low Ca^<2+> and a high Mg^<2+> solution or 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) at 10^<-5> M, but not by DL-2-amino-5-phsphonovaleric acid (AP-5) at 10^<-5> M.Judging from the response time, some NTS neurons may be innervated directly by AP神经元的神经末端。这些结果表明，Ap神经元介导的V1受体的加压素兴奋通过谷氨酸通过NMDA和非NMDA受体或仅非NMDA受体传递到NTS。散发反应是一种极其复杂的防御机制。呕吐是一种反射，它在呕吐中心集成了内脏传入和有效的途径，该中心被认为位于延髓。使用免疫组织化学技术，已经证明了参与大鼠和人类散发物质的物质的神经纤维的存在。我们使用 ^3H-固定p作为雪貂中的结合配体，观察到在这些区域中，在这些区域中，速度基因基-1受体在这些区域的定位。由NK-1受体拮抗剂（HSP-117（1.0μg）和CP-99,994（7.5μg）抑制了吗啡或硫酸铜诱导的催吐反应。这些结果表明，AP，NTS中的NK-1受体和迷走神经的背运动核可能参与了弹性机理。