延髓腹外侧区神经元含多种递质或调质

有整合循环、呼吸、躯体传入、内分泌等多种功能。其表面结构是维持心血管活动的重要脑区

它作为重要的心血管活动中枢愈来愈受到人们的重视。临床和实验研究表明

针刺“内关”具有改善心绞痛患者症状

改善左心功能状态和促进急性心肌缺40 healthy rabbits were anesthetized with 20% urethane and divided into 4 groups in same number:1)electroacupuncture group physiological saline was applied locally on the S area of the ventral surface of the medulla:2)naloxon group

naloxon (5mg/ml.PH 6.5-7)was applied on the S area:3)propra- nolol group

propranolol (5mg/ml.pH 7.0)was applied on the S area;4) control group

physiological saline was applied on the S area.The state of regional myocardial ischemia of the rabbits was caused by ligating the LAD for 20 minutes.The changes of the blood pressure and the ST values of sta- ndard lead Ⅱ of ECG were observed before ligating and

at 5′

10′

15′

20′

25′

30′

35′

40′

45′

50′

55′ and 60′ after loosening respectively.Electro- acupuncture was applied on “Neiguan” points bilaterally at 10′ after ligating for 60 minutes (intensity 6-8 volt

frequency 60/min).The average potential changes of the ST values of standard lead Ⅱ of 5 times were used as the index to evaluate myocardial ischemia and its recovery course. The followings are the main results of our observation: There were no statistical defference

of blood pressure and the ST values between the four groups before ligation.At 10 minutes ofter ligation

the ST values were elevated markedly

but there were no statistical significances be- tween the four groups. During electroacupuncture

blood pressures in the four groups decreased gradually

but comparing with electroacupuncture group

blood pressure in the naloxon group and the control group decresed markedly

the propranolol group was the same as the electroacupuncture group:the ST values in the four groups recovered gradually

but the recovering in the naloxon and the control group was sluggish and there was statistical difference comparing with electroacupu- nture group

(there was)and no statistical difference was observed between propranolol group and electroacupuncture group. The above mentioned results show that there is an improved effect of ele- ctroacupuncture on acute ischemic myocardial injury.The effect can be reversed by naloxon applied locally on the S area of the ventral surface of the medulla.