激动中枢组胺能受体对应激大鼠颈动脉窦压力感受性反射重调定的影响  

Effects of central histaminergic receptor activation on carotid sinus baroreceptor reflex resetting in stressed rats

作　　者：王国卿[1] 周希平[1] 黄伟秋[1] 

机构地区：[1]苏州大学医学院基础医学系生理学教研室,苏州215007

出　　处：《生理学报》2003年第1期29-35,共7页Acta Physiologica Sinica

摘　　要：应激 1周的大鼠 ,麻醉后孤离双侧颈动脉窦区 ,将不同窦内压 (ISP)与其对应的平均动脉压 (MAP)值进行Logistic5个参数曲线拟合。根据所得ISP-MAP关系曲线及其特征参数 ,分别观察侧脑室 (i c v )注射和孤束核(NTS)内注射组胺受体拮抗剂对颈动脉窦压力感受性反射 (CSR)的影响 ,并与相应的非应激CSR水平进行比较。结果如下 :(1)应激导致ISP-MAP关系曲线显著全面上移 ,窦内压和增益 (ISP-Gain)关系曲线中部明显下移 ,反射参数中阈压 (TP)、饱和压 (SP)、调定点 (setpoint)和最大增益时的窦内压 (ISPGmax)值增大 ,MAP反射变动范围 (MAPrange)及反射最大增益 (Gmax)减小 ;(2 )I c v H1或H2 受体拮抗剂氯苯吡胺 (CHL) 5 μg或西咪替丁 (CIM ) 15 μg ,在 2 0min内均可明显减弱应激对CSR的上述改变 ,CIM的这种减弱作用不如CHL的显著 ;(3 )NTS内注射CHL(0 5 μg)或CIM (1 5 μg) ,对应激所致CSR变化的影响与i c v CHL或CIM后的相类似 ;(4)分别i c v 和NTS内注射CHL或CIM后 ,均不能使应激的CSR水平完全恢复到相应的非应激对照水平。以上结果提示 ,应激引起CSR重调定 ,反射敏感性下降 ;其部分机制可能是激活中枢组胺能系统 ,通过中枢组胺能受体 (H1和H2 受体 )尤其是H1受体介导而发挥作用 ;下丘脑To determine the effect of stress on carotid sinus baroreceptor reflex (CSR) and whether or not central histaminergic receptors modulate the CSR under stress, the characteristics of CSR were analyzed by using an isolated carotid sinus preparation in Wistar rats. Animals were divided into two groups at random: unstressed group ( n= 42) and stressed group ( n= 41). According to the site of microinjection of histaminergic receptor antagonists, each group was subdivided into a group of intracerebroventricular injection (i c v ) and a group of microinjection into the nucleus of the solitary tract (NTS). The volume of injection into the lateral cerebroventricle and NTS was 5 μl and 1 μl, respectively. Stressed groups were subjected to unavoidable electric foot shock twice daily for a week, each session of foot shock lasted 2 hours. The left and right carotid sinus regions were isolated from the systemic circulation under anesthesia with pentobarbital sodium in all rats. The intracarotid sinus pressure (ISP) was altered in a stepwise manner to trigger CSR from 0 to 280 mmHg at every step of 40 mmHg and 4 s, and then returned to 0 mmHg in similar steps. ISP and mean arterial pressure (MAP) were recorded simultaneously. ISP-MAP relationship curve was constructed by fitting to the logistic function with five parameters. The CSR parameters and the ISP-MAP relationship curve were separately compared statistically. The main results obtained are as follows. (1) Stress significantly shifted the ISP-MAP relationship curve upwards and obviously moved the middle part of ISP-Gain relationship curve downwards, and decreased the value of the MAP range and maximum gain (G max ), but increased the threshold pressure (TP), saturation pressure (SP), set point and ISP at G max (ISP Gmax ). (2) I c v of H 1 receptor antagonist chlorpheniramine (CHL, 5 μg) or H 2 receptor antagonist cimetidine (CIM, 15 μg) significantly diminished the above mentioned changes in CSR performance induced by str

关 键 词：颈动脉窦压力感受性反向 应激 氯苯吡胺 西咪替丁 侧脑室注射 弧束核 平均动脉压 

分 类 号：R33[医药卫生—人体生理学]