头端延髓腹外侧区在侧脑室注射新斯的明所致升压中的作用

ROLE OF ROSTRAL VENTROLATERAL MEDULLA IN THE PRESSOR RESPONSE TO INTRACEREBROVENTRICULAR INJECTION OF NEOSTIGMINE

实验在47只乌拉坦(700m/kg)、氯醛糖(35mg/kg)麻醉,肌肉麻痹,人工呼吸的家兔上进行。结果观察到,侧脑室注射(icv)新斯的明引起血压升高,心率(HR)先减慢后有加快趋势,股动脉血流量(FBF)与股动脉血管通道性(COND)减小,左心室内压(LVP)增大,肾交感神经放电(RND)增加,延髓腹外侧头端(rVLM)微量注射阿托品则引起血压下降,HR减慢,FBF与COND增加,LVP与RND减小,若在icv新斯的明之前,预先向rVLM注入阿托品,可阻断新斯的明的升压效应,上述结果提示,rVLM是icv新斯的明升压效应的重要部位,rVLM区M受体功能完整是这种升压作用的关键因素。

Experiments were carried out on 47 urethane-chloralose anesthetized andflaxedil immobilized rabbits under artificial respiration.Intracerebroventricularinjection(ICV)of neostigmine(100μg/200μl)caused a marked increase inblood pressure(BP),left ventricular pressure(LVP)and renal sympathetic nervedischarge(RND),While femoral blood flow(FBF)and conductance(COND),were decreased and the heart rate(HR)was initially reduced and then slightlyincreased.Microinjection of atropine(0.25μg/site)into the rostral ventrolateralmedulla(rVLM)caused a decrease in BP,HR,RND and LVP and a increase inFBF and COND.Pretreatment of atropine injection into rVLM before ICV ofneostigmine blocked the pressor response of neostigmine. These results indicate that rVLM is important for the pressor response to ICVneostigmine,which may be mediated via cholinergic muscarinic receptors inrVLM.