To verify the ancient theory of rather missing the acupoint than missing the meridian, acupuncture at nonacupoint on meridian and acupuncture at nonacupoint off meridian were performed, respectively. The blood perfusion (BP) on the calf around bladder meridian area was measured with a laser Doppler perfusion imager before, during, and after acupuncture. The whole scanning field was divided into seven subareas, and mean BP on each area was calculated. The ratio of mean BP between a subarea and a reference subarea was gotten, and then the change rate was calculated as ratio change rate (RCR). The results showed that RCR on bladder meridian area and around Chengshan (BL57) during or after acupuncture at nonacupoint on meridian was significantly higher than that at nonacupoint off meridian, which supports the ancient theory. Such differences may be attributable to some factors that can facilitate the signals transmission and produce a better acupuncture effect, such as richer nerve terminals, blood vessels, and mast cells which can produce stronger signals on the acupoints and the low hydraulic resistance channel along meridians which plays a role of signal transmitting channel to get a better effect of acupuncture.
The ancient theory of “rather missing the acupoint than missing the meridian” is an important principle to guide the acupuncture clinic originated from Yang’s “Compendium of Acupuncture and Moxibustion” in
Acupuncture effect was represented partly by blood perfusion (BP) or blood flow (BF) in several experiments [
20 healthy volunteers were from China Academy of Chinese Medical Sciences and Beijing University of Chinese Medicine. Of them, 11 were male and 9 female, ranging in age from 19 to 55 years. They had no illnesses or obvious discomfort within a week and had not taken medicine in the past one month before the test. All the participants had an adequate understanding of the procedure and purpose of this trial.
The BP on the skin of calf around bladder meridian area was measured by a PeriScan PIM II laser Doppler perfusion imager (made in Sweden). The instrument was set to medium resolution and 50 × 64 (3200) points. The scan area was about 15 × 20 cm and each scan took about 3 minutes. The acupuncture needle of 0.30 × 30 mm (Huan Qiu, Suzhou, China) was used in this test. The test was carried out in a dark room. The room temperature was kept between 26 and 28°C. The fluctuation in the temperature was less than ±1°C during one experiment.
Each subject received twice measurements with an interval of more than two days between the two measurements and chose to acupuncture at nonacupoint on the meridian first or at nonacupoint off the meridian first at random. Before the measurement, subject was asked to lie on bed for ten minutes to adapt to the room temperature. Measuring of BP before acupuncture was given for one time and then the acupuncture was started.
Acupuncture was performed at two selected points. One point was located on 2 cm above Chengshan (BL57), on Bladder Meridian of Foot Taiyang, as nonacupoint on the meridian, and the other point on Chengshan (BL 57) level, 2 cm lateral to Bladder Meridian of Foot Taiyang, as nonacupoint off the meridian (Figure
The position of acupunctured points and the area divisions for analyzing mean blood perfusion. ○ denotes Chengshan (BL57), and the broken line denotes bladder meridian. △ denotes the nonacupoint on bladder meridian, and □ denotes the nonacupoint off bladder meridian. The upper set of the figure is the direction of foot, and the inferior set is the direction of head.
The procedure of the experiment. The number in
The whole measured area on the calf was divided into seven subareas (Figure
After the seven subareas were divided, mean BP level in each area was calculated automatically by LDPIwin2.5 software which was obtained with the instrument. An important data analysis was achieved in our previous study that the BP at a reference area was gotten to represent the whole body change which was influenced by various unknown factors and by nonspecific effect of acupuncture [
After the ratio between the BP on one area and the BP on reference area
Ratio change rate of blood perfusion on difference areas during various periods of acupuncture (Mean ± SD,
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From the Table
Ratio change rate (RCR) of BP on bladder meridian (area 3) when needling at nonacupoint on bladder meridian (blue line) and at nonacupoint off bladder meridian (red line). * denoting a significant difference (
The difference in the RCR of BP on control area (area 4) that is similar to the size of meridian area (area 3) was not significant between on meridian group and off meridian group during most periods. However, at time 9 after withdrawal of the needle, the difference became significant, which indicates that acupuncture at nonacupoint on the meridian possesses a stronger lasting effect.
The local effect around needling points was compared between acupuncture at the two nonacupoints (Figure
The local effect of ratio change rate (RCR) of BP around the needling points. Blue line denotes RCR in acupuncture at nonacupoint on the meridian, and red line denotes RCR in acupuncture at nonacupoint off the meridian. * denoting a significant difference (
The holistic effect (area 6) still existed in on meridian group even when the pure holistic effect without local effect and meridian effect was diminished by calculation of the ratio, while it was nearly diminished (around zero) in off meridian group (Figure
Ratio change rates of BP in on meridian group (blue line) and off meridian group (red line). * denoting a significant difference between the two groups.
From the result of the previous experiment, a stronger effect of acupuncture on blood perfusion was found when needling the nonacupoint on meridian than needling the nonacupoint off meridian.
Many studies focused on comparing the difference of acupuncture effects between needling acupoint on meridians, and nonacupoint off meridians while little is known about the difference between needling nonacupoint on meridian and nonacupoint off meridian. Zheng et al. measured the blood perfusion at deep tissue using a needle-type detector and found little difference in increase of BP during acupuncture [
It remains a question that what is the role of meridian in acupuncture clinic. The ancient theory told us that you will make a mistake if you do not know the meridians. But modern acupuncture pays little attention to the importance of meridians. The precision of selecting an acupoint during acupuncture is an important factor to influence the acupuncture effect. In Song dynasty, a doctor must pass an examination of selecting acupoints on a bronze acupuncture figure in that water can flow out if he needles an acupoint correctly. The precision of selecting an acupoint depends on acupuncturist’s experience at present during which the position of a selected point may miss the real acupoint but still on the meridian line or miss the real acupoint and miss the meridian at the same time. Acupoints along fourteen meridians are the main points used to apply acupuncture. Many acupoints along one meridian have similar function in treatment of the disease. The mechanism of the fact was speculated by ancient doctors that a “
Zhao et al. found an increase in gastric electric activity when acupuncturing Sibai (ST2) and Dichang (ST4) along the stomach meridian; however, no obvious changes were found when acupuncturing a nonmeridian point beside Sibai (ST2) and a point on small intestine meridian [
Our new result showed that when the points have the same departure from the acupoint, the local effect and meridian effect in nonacupoint are significantly higher than that in nonmeridian point. To see the local effect around the needling point immediately after acupuncture and combined with the data obtained before, 60.1%, 48.5%, and 20.5% increase in turn in acupoint, nonacupoint on meridians, and nonacupoint off meridians, which further proved the rule of acupuncture effect related to acupoints and meridians. The rule has been described roughly in Zhang’s book “what is the meridian” in 1997 [
An illustration of acupuncture effect related with acupoints and meridians. There is a descending of effect from acupoint both along meridian and perpendicular to the meridian while the falling gradient is smooth along the meridian than perpendicular to the meridian.
The mechanism of the strongest acupuncture effect of needling acupoints might be due to the dense distributions of nerve terminals, blood vessels, and mast cells at the acupoint sites [
The stronger effect of acupuncture at nonacupoints on meridians can be attributed to the existence of low hydraulic resistance channel along meridian which was found by Zhang et al. [
Nerve terminals, blood vessels, and mast cells can be regarded as the substance of acupoints through which stronger acupuncture signals can be produced to get the best effect. The low hydraulic resistance channel of interstitial fluid represents the entity of meridian channels which plays a role of signal transmitting channel to get a better effect of acupuncture.
All the authors declare that they have no conflict of interests.
This work was supported by the grants (no. 30572307 and no. 308401) from National Natural Science Foundation of China.