摘要
目的 :深入探讨脑内注射SP的心血管效应及其与去甲肾上腺素能系统的关系。方法 :家兔乌拉坦静脉麻醉 ,侧脑室注射SP或预先注射肾上腺素能受体阻断剂酚妥拉明、哌唑嗪、育亨宾。记录给药前后平均动脉血压(MAP)、左室收缩压 (LVSP)、左心室收缩末期压 (LVEDP)、室内压最大上升速率 (+dp/dtmax)和下降速率 (-dp/dtmax)、心肌收缩成分实测最大缩短速度 (Vpm)、心率 (HR)。观察脑室注射SP后小脑延髓池脑脊液中NA含量的变化。结果 :①与对照组比较 ,icvSP可引起HR、LVSP、LVEDP、+dp/dtmax、-dp/dtmax和Vpm值明显增加 (P <0 .0 5 ) ,同时 ,小脑延髓池脑脊液中NA含量显著升高 (P <0 .0 5 )。②酚妥拉明或哌唑嗪预处理可显著减弱脑室注射SP引起心血管增强效应 (P <0 .0 5 ) ,但育亨宾预处理对注射SP引起的心血管效应无明显影响 (P <0 .0 5 )。结论 :①脑内注射SP可增强心脏的收缩功能、升高动脉血压。②脑内α1肾上腺素能受体可能参与侧脑室注射SP的心血管增强效应。③中枢应用SP可促进NA能神经元释放NA或抑制突触前膜重摄取NA。
Aim: To investigate the role of intracerebroventricular (icv) injection substance P(SP) in cardiovascular regulation and the relationship with noradrenergic system. Methods: Rabbits anesthetized with urethane were intracerebroventricularly given SP in presence or absence of phentolamine, prazosin, yohimbine. Cardiovascular responses including heart rate (HR), mean arterial blood pressure (MAP), left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure(LVEDP), the maximum velocity of ascen-(ding) or descending in intraventricular pressure(±dp/dt_(max)) and the maximum shortening velocity(Vpm) of myocardial contractile element were recorded, and changes of NA content in cerebrospinal fluid(CSF) were determined in rabbits with icv injection of SP. Results: ① icv SP elicited significant increased of HR, MAP, LVSP, LVEDP, +dp/dt_(max), -dp/dt_(max), Vpm and the levels of NA in intracisternal CSF 30 min after injection. ② Pretreatment with phentolamine, prazosin, but not yohimbine, attenuated icv SP-induced cardiovascular responses compared with controls(P<0.05). Conclusion: ① icv SP can produce positive inotropic and chronic response in myocardium and pressor response in intact rabbits.② α_1 adrenoceptors may be involved in the cardiovascular responses to icv SP. ③ Central administration of SP can increase the release of NA or inhibit reuptake of NA, which may be responsible for an important mechanism of SP-potentiated cardiovascular responses in brain.
出处
《中国应用生理学杂志》
CAS
CSCD
北大核心
2004年第3期254-258,共5页
Chinese Journal of Applied Physiology
基金
贵州省科学技术基金资助项目 ( 99963 0 84)
关键词
P物质
去甲肾上腺素
脑脊液
心血管效应
侧脑室
substance P
noradrenaline
cerebrospinal fluid
cardiovascular response
intracerebroventricular
