The efficacy of acupuncture-moxibustion for hypertension is often experienced by many clinicians. Nevertheless the mechanism whereby the therapy improves the symptoms has been scarcely elucidated. Our present study was designed to examine some effects of acupuncture upon the organism, especially upon the renal function which is implicated in hypertension.
Experiment I
Acupuncture therapy was undertaken four times on a patient with essential hypertension who was given no hypotensive drugs. In each therapy, needles (No. 2, Seirin) were perpendicularly inserted to the depth of 1.5cm at V₂₀ Fengchi, VU₂₁ Weishu, and G₃₆ Zusanli and left there for 15 minutes. The blood samples and urine were collected three times: before the insertion, 15min. and 60min. after withdrawing the needles. At the same time, blood pressure, pulse, and the amount of urine were measured. The amount of Na, K, Cl, kallikrein, catecholamines, etc. was measured in urine. The renin activity and the concentration of aldosterone, catecholamines, and BUN were determined in the blood. Result: a marked increase was seen in the excretion of urine, Na, and Cl. An upward tendency of kallikrein excretion which is correlated with urine volume, and a downward tendency of renin in the blood were found. Blood pressure and pulse showed a slight tendency to decline. However, neither catecholamines in the blood, nor K in urine changed significantly.
Experiment II
Subjects were two healthy adult men. Urine was collected once an hour for twenty-five times by means of a balloon inserted in the bladder. Immediately after the twenty-first collection, acupuncture stimulation was given to VU₂₁ Weishu in the same manner as Exp. I. With the same measurements and determinations undertaken, a marked increase of urine, Na, and Cl excretion was observed 15min. after withdrawing the needle.
Experiment III
Subjects were three healthy adult men. Urine was collected for two days. The amount of urine and the electrolyte content were calculated on a per hour basis. Without having breakfast after rising, the subjects were given a transfusion of glucose-electrolyte solution, equivalent to the calculated urinary output, every hour for four hours. The VU₂₁ Weishu was stimulated in the same manner two hours after the onset of the first transfusion. Result: a marked increase was seen in the excretion of urine, Na, and Cl.
Conclusion
It can be seen from the above that acupuncture stimulation to the VU₂₁ Weishu facilitates the selective excretion of Na and Cl in the urinary tubule.