Influence of Electroacupuncture on Hypertension Vascular Dementia and Its Red Cell Immune Function in the  Rat

Mo Feizhi, Li JianQiang, Lei Liping

Abstract  Objective: To probe into the effect of electroacupuncture (EA) on vascular dementia and red cell immune function in the rat. Methods: 30 SD rats were made into renal hypertension rats (RHR) by clamping the kidney arteries with silver clip. 42 days later, their bilateral common carotid arteries were blocked repeatedly to cause cerebral ischemia. The Hypertension vascular dementia model was then set up. Then they were randomly divided into VD model group, EA group and medication group (Dihydroergotoxine, DHET), with 10 cases in each group. The therapeutic course was 28 days. The ability of learning and memory was using an observed by water maze, and the function of red blood cell immune was detected after treatment. Results: the latency of the EA group and medication group was shorter than that of model group (P<0.05, P< 0.005), and that of EA group was shorter than medication group (P<0. 05, P<0.005). EA and medication could increase the RBC-C₃b receptor flower circle rate and reduce the RBC-IC flower circle rate significantly (P<0.05, P<0.01). Conclusion: The results indicated that EA therapy could raise the ability of learning and memory and improve the function of red cell immune in VD rats, while the therapeutic effect of EA is better than DHET.

Key Words Vascular Dementia Electroacupuncture Water maze Red blood cell immune function Rat

Vascular Dementia (VD), is a dementia syndrome caused by cerebral vascular disorder, usually accompanied with hypertension, coronary heart disease, etc. It has been confirmed that hypertension is the independent high risk factor of VD. Repeated cerebral ischemia often leads to irreversible injury of hippocampus, cortex and other structures of the brain, and thus the dementia symptoms appear. Therefore, we used renal hypertension (RH) rats to make a VD model for analyzing the effect of EA on dementia and red blood cell immune function. The present study is also aiming at providing some behavioral and immunological evidence for the therapeutic principles of “promoting blood circulation, dredging meridians, replenishing essence and enriching marrow" ^[1] in treatment of deficiency and blood stasis types of VD.

Materials and Methods 

60 male Spraque-Dawley (SD) rats, 80-120 g/b.w., were used in this study. Blood pressure of the rat tail artery was detected three times before making RH model. 10 of the 60 rats whose kidney artery was explored without being clamped were taken as sham-operation and the other 50 animals were made into RH model according to Huang's method^[2] . Blood pressure was detected on the7^th , 14^th, 28^th, 42^nd day after inducing RH. The place navigation test was then conducted 4 times per day from the 36th to the 42nd day after RH. The mean value was considered as the result achieved that day. The blood pressure of 50 RH animals increased to 20.98±1.66 Kpa on the 28 day and 22.29±1.30 Kpa on the 42 day after operation. 10 of 50 animals selected randomly were taken as control group (RH control), another 10 animals which received operation but without receiving clamping of the kidney artery were taken as sham operation group (RH sham operation). Bilateral common carotid arteries were occluded by using a microarterial clamp for 10 min, and released for 3 min for blood reperfusion, and then occluded again for another 10 min and then released again. The vascular dementia (VD) was then produced successfully. These animals were randomly divided into three groups: VD group (n=10), EA group (n=10), and medication group (n=10). EA of Baihui (DU 10) and Dazhui(DU 14) points was given to the animals of EA group by connecting the two needles to a device (G-6804, made in Shanghai) with output of electric current 4-6 mA, voltage <3 V and frequency 2-3 Hz and duration of 20 min. EA stimulation was given once per day, with 5 day being a therapeutic course, 4 courses in total and 2 days' break between two courses. 7.5% dihydroergotoxine (DHET) 2 ml was given to the animals of the medication group, with the courses being same as EA group. The animals in other groups were kept in the same experimental conditions, as t he animals of EA and medication groups, but received no treatment.

Place navigation test and spatial probe test of animals in all groups were detected on the 78th and 82nd day after operation respectively. Swimming duration in each quadrant was recorded. Put the plat 3cm above the water surface and tested swimming ability of the animals. The time which the animal reached the plat was also recorded^[3,4]. Finally, blood samples were taken for detection of RBC-C3bRR and RBC-ICR^[5].

Collected data were processed statistically with Student test by using Microsoftware Excel 8.0.

Results

Water maze test: The latency of swimming time of the animals in acupuncture and medication groups was shorter and shorter with treatment (P<0.05, P<0.005) and that in acupuncture group was shorter than that of medication group (P<0.05, P<0.005). Compared with the latency of RH sham operation group, that of EA group was significantly longer on the 78^th day after operation (P<0.05) and there was no significant difference from 79^th to 82^nd day after operation (P> 0.0 5). The latency (except the 82^nd day) of the medication group was longer than that of the RH sham operation group (P<0.05-0.005, Table.1). Spatial probe test: The duration while the animals in VD group stayed on the platform was significantly shorter than those of the other groups (P<0.05-0.005). There was no significant difference between EA and RH group or RH sham-operation control group (P>0.05). The latency of the medication group was shorter than that of the EA or RH sham operation groups (P<0.05, P<0.05). There was no significant difference between medication and RH group or RH sham operation group. There was also no significant difference among all groups in swimming ability (P>0.05).

Table 1. Comparison of different groups in Swimming 

latency of water maze test (seconds, M±SD)

Compared with control group: *P<0.05, **P<0.01, ***P<0.005

Compared with RHR sham-operation group: ��?lt;/span>P<0.05, △△P<0.01,

△△��?lt;/span>P<0.005

Compared with VD model group: ▲P<0.05, ▲▲P<0.01, ▲▲▲P<0.005

Comparison between acupuncture group and medication group: #P<0.05, ##P<0.01, ###P<0.005

RBC-3b and RBC-IC detection: Compared with control group, RBC-C3bRR of all the groups except RH group decreased significantly (P<0.05-0.001) particularly in VD group. RBC-ICR of the animals in every group increased significantly (P<0.05-0.001) especially in VD group. Compared with sham operation group, RBC-C3b RR of EA and medication groups had no any significant changes. Concerning changes of RBC-ICR, there was no evident difference between EA group and RH sham operation group, while that of medication group was higher considerably than that of RH sham operation group (P<0.001). Both decrease of RBC-C3b RR and increase of EBC-ICR of VD control group had a significant difference (P<0.001). Compared with VD model group, RBC-C3b RR of the EA and medication groups increased and RBC-ICR of those decreased significantly (P<0.005, P<0.01). There was no significance between the RBC-C3bR of EA group and that of the medication group. RBC-ICR of EA group was significantly lower than that of medication group (P<0.05) (Table 2).

Table 2. Comparison of RBC-C3bRR and RBC-ICR

 of the animals among 6 groups (%, M±SD)

Compared with control: *P<0.05, **P<0.01, ***P<0.005

Compared with RHR sham-operation: △P<0.05, △△P<0.01, △△△P<0.005

Compared with VD model: ▲P<0.05, ▲▲P<0.01, ▲▲▲P<0.005

Comparison between acupuncture group and medication group: #P<0.05, ##P<0.01, ###P<0.005

Discussion

The results suggested that EA could improve learning and memory ability in the V D rat and its effect was better than DHET. Learning and memory ability of the VD rats were obviously weaker than those of the other groups, while the swimming ability had no significant difference among different groups. It indicated that the longer latency of VD rats in water maze was not caused by muscle weakness. Chinese traditional medical theory emphases that the brain is the sea of the marrow which is kept in the brain from top part of the head (Baihui-GV 20) to the lower (Fengfu-GV 16). The Du meridian, considered as the sea of the yang meridians, goes up to Fengfu(GV 16) and then enters into the brain. Dazhui(GV 14) of Du meridian is the crossing point of the yang meridians of the hand and the foot. According to the theory of TCM, VD results from insufficiency of marrow of the se a and insufficient nutrition of the brain due to deficiency of blood and Qi , liver and kidney or Qi stagnation, blood stasis and blockage of meridians by phlegm.

Acupuncture of Baihui(GV 20) and Dazhui(GV 14) could dredge meridians, activate blood circulation, eliminate stagnation, and resolve phlegm, and thus could improve dementia.

The membrane surface of red blood cells has C3b receptors (RBC-C3bR), while these receptors are the main material basis of the red blood cell immune adherence function. RBC-C3bR can adhere to immune complex (IC) formed by combination of antigen and antibody. It can also activate the bypass to clean the antigen binding to the complement. RBC-IC1 receptors constitute about 90-95% of the total IC receptors in the blood circulation system. RBC is the main system for cleaning IC. Immune activities of RBC changed in different degree following brain ischemia. Immune function of RBC usually decreased after brain ischemia. Some scholars held that RBC plays an important role in cerebral stroke and ischemia^[8].

RBC-C3bR flower circle rate of rats with high blood pressure (in control, RH model and RH sham operation groups) in VD group decreased, while RBC-IC flower circle rate in these groups increased, it suggested that the immune activity of RBC decreased after ischemia. Immune adherence of membranous C3b receptors reduced and thus the function of IC clearance lowered. The mechanism may be abnormal changes of the adherence of the blood and the blood flow due to high blood pressure and/or repeated cerebral ischemia. As a result, the slow blood flow can not clear away the fibroprotein sufficiently , and lead to blood stagnation" After treatment, acupuncture and medication could reverse the decreased RBC-C3bR rate to increase, and the increased RBC-IC rate to decrease. The results of our experiments suggested that both acupuncture and DHET could improve the RBC immune adherence activity and enhance the capability of the body in clearing away IC and the effect of acupuncture was better than DHET.