In order to analyse the mechanism of acupuncture on the regulation ac- tion of the abnormality of cardio-vascular function and the possible pathwa- ys

experiments were performed on 20 rabbits weighing 2.2-3.5 Kg and were operated under urethane anesthesia. The arterial blood pressure

left ventri - cular pressure (LVP)

maximum rate of left ventricular pressure rise time to peak (LV dp/dt) and ECG(Lead Ⅱ) were recorded simultaneously on the model RM-86 polygraph. A bipolar stimulating electrode was stereotaxically implanted into the hypothalamus(P 1-3

R 0.5-2

H-2-4) according to Sawyer's atlas. An electrical stimulation was giv ento the hypothalamus in conscious status. Parameters of the stimulation are as follows: A train of squnre pulse of 50 Hz

wave width 1 msec

intensity 0.5-1.3 mA. Each train was 15-30 sec in duration and separated by an interval of 5-10 minutes. After the stimulation of hypothalamus

changes of cardio-vascular function showed marked ischemic ECG changes such as bradycardia

ventricular extrasystole

ST segment depression or elevation

T-wave peaking or flattening and showed marked rise of arterial blood pressure

LVP

LVdp/dt

then the effects of acupuncturing "Neiguan"or by intravenous injection of β-adrenergic receptor blockade propranolol

adrenergic receptor blockade phentolamine and M-cholinergic blockade on the abnormality of the central cardio-vascu- lar function were observed. the results were summarized as follows: 1. The values of systolic blood pressure

diastolic blood pressure

LVP

LVdp/dt induced by the stimulation of hypothalamus were 57.34±6.58 mmHg (mean±SE)

30.8±3.16 mmHg

40.08±7.05 mmHg

633.34±101.01 mmHg/sec higher than the basal values obtained before stimulation

re- spectively. But the heart rate decreased by 62.82±11.48 cycle/minute than the basal values obtained before stimulation. Most of the rabaits also showed marked simultaneously ischemic ECG changes. 2. After acupuncturing "Neiguan" points for 20-30 minotes

the rise of arterial blood pressure

LVP

LVdp/dt induced by the stimulation of hypo- thalamus were markably relieved as compared with those before acupunctu- re

and the effect of heart rate decreasing was also weakened. Before and after acupuncturing "Neiguan"

there was significant difference. The myo- cardial ischemic changes were remarkably improved simultaneously and the ventricular extrasystole almost disappeared. It appeared to be a modulating action in the acupuncture on the abnormality of central cardio-vascular function. 3. The abnormal changes of cardio-vascular function induced by the stimulation of hypothalamus were partially reversed by intravenous inje- ction of propranolol

phentolamine and atropine. The rise of arterial blo- od pressure

LVP

LVdp/dt induced by the stimulation of hypothalamus were reversed by propranolol. The ventricular extrasystole and myocardi- al ischemic changes induced by it almost disappeared by phentolamine. The decrease of the heart rate induced by it disappeared by atropine. Based on the above results

it could be concluded that acupuncturing "Neiguan" to regulate the central cardio-vascular function might be carried out through adrenergic and cholinergic nervous system.