我们在麻醉的家兔上观察到

刺激腓深神经可使压力感受性反射发生重调定

表现为压力感受性反射的敏感性增强

而对基础血压水平无明显影响。进一步的实验表明。在过深的麻醉条件下

刺激躯体神经对压力感受性反射的重调定作用变得不明显

提示麻醉剂能影响刺激躯体神经对压力感受性反射重调定的效应。根据梅俊等的报道

电针“足三里”和电刺激腓深神经能在脊髓引导到相同的诱发电位。故本实验试图在清醒家兔上

观察电针“足三里”对压力感受性反射的影响。实验在22只清醒家兔上进行。在局麻下Experiments were carried out on 20 conscious rabbits. Phenylephrine(20 μg/kg

i

v.) and sodium nitroprusside (30μg/kg

i.v.) were respectively used for changing arterial blood pressure. Arterial pressure and heart rate were: recorded simultaneously. The mean arterial pressure (MAP) heart rate (HR) regression line was constructed and the effect of electroacupun- cture at "Zusanli" (4 mA

3 Hz

0.5 ms

for 20 min) on baroreceptor reflex was observed. During electroacupuncture

no significant change in basal MAP and HR was observed but the slope of MAP-HR regression lines was steeper than that during control period

i.e

the baroreceptor reflex became more sensitive. In anesthetized animals

the compotind action potentials of the sciatic nerve were recorded. Electroacupuncture of the "Zusanli" acupoint was shown to excite the group Ⅰ

Ⅱ and Ⅲ afferent fibers in the sciatic nerve. These results suggest that electroacupuncture results in resetting of the baroreceptor reflex via activating the somatic afferents

thus enhancing the ability of baroreflex to correct abnormal blood pressure.