【摘要】 在31只麻醉猫观察了颈动脉窦压力感受器(CSB)在低血压时的快速重调现象。所得结果如下:(1)切断颈部迷走神经、颈交感神经和双侧窦神经条件下,以记录窦神经单位传入放电的方法,测得急性失血性低血压时(70mmHg,10min,n=13),其CSB阈压(TP),正常发放压(NFP)和饱和压(SP)分别从正常血压水平(123.0±2.9mmHg)的61.0±1.6mmHg,111.2±1.7mmHg和163.0±2.8mmHg下降为41.4±0.8mmHg,83.7±1.7mmHg和125.6±8.2mmHg,各相应参数间均有非常显著性差异(P<0.001)。低血压时CSB功能曲线较正常血压时向左上方移位,曲线斜率的变化在统计学上没有意义(P>0.5)。如颈交感神经保持完整(n=8),失血性低血压猫CSB的TP,NFP和SP与常压时相比未发生变化。(2)在硝普钠诱发的低血压猫(68.0±1.2mmHg,10min,n=10),其CSB的TP、NFP和SP与正常血压时(128.5±4.8mmHg)相比,分别从80.0±2.7mmHg,131.0±3.3mmHg和181.9±4.6mmHg下降到58.1±3.6mmHg,96.0±3.6mmHg和133.8±4.3mmHg,各相应参数间均有非常显著性差异(P<0.001)。CSB功能曲线移位方向和斜率的变化与失血性低血压时相似。上述结果表明,猫CSB在失血性或药物性低血压10mir后产生快速重调。颈交感神经对失血性低血压10min时CSB的重调有去除作用。更多还原

【Abstract】 Rapid resetting of carotid sinus baroreceptor (CSB) daring bypotension was studied in 31 anesthetized cats. The results obtained were as follows: ( 1 ) After the section of vagi, cervical sympathetic nerves and carotid sinus nerves, single-unit baroreceptor discharge was recorded from the carotid sinus nerve. The threshold pressure ( TP ), normal firing pressure ( NFP ) and saturation pressure ( SP ) of the baroreceptor were decreased from 61.0±1.6 to 41.4±0.8mmHg ( P<0.001 ) , from 111.2 ± 1.7 to 83.7± 1.7mmHg (P<0.001)and from 163.0±2.8 to 125.6±3.2mmHg (P<0.001), respectively, while the blood pressure was lowered from control ( 123.0 ± 2.9mmHg ) to hypotensive level < 70mmHg for 10 min ) by bleeding ( n-13 ) . The function curve of CSB after hypotension was shifted to the left of those of normotensive state with no significant change in slope of the curves (P>0.5) . While the cervical sympathetic nerves were intact ( n-8 ) , the TP, NFP and SP were altered insignificantly. ( 2 ) During sodium ni-troprusside evoked hypotension (68.0±1.2mmHg for 10min, n-10), .the TP , NFP and SP were lowered from 80.0 ± 2.7 to 58.1 ± 3.6mmHg (P<0. 001 ) , from 131.0 ± 3.3 to 96.0±3.6mmHg ( P<0.001 ; and 11.8 ± 4.6 to 133.8± 4.3mmHg (P<0.001) , respectively, The displacement and the slope of CSB function curves were similiar to those of hemorrhagic hypotension . The results demonstrated that the rapid resetting of CSB did occur in 10 min after hemorrhagic and sodium nitroprusside evoked hypateosion in cat. Cervical sympathetic nerve exerted a deresetting effect on CSB activity- daring hemorrhagic hypotension for 10 min.更多还原