Effects Of Neiguan Acupoints Specificity On Myocardial Ischemia Calcium Channel And Its Relationship With Chronic Stress Depression

Purpose:In clinic, acupuncture therapy is applicable to many kinds of disease, including myocardial ischemia(MI). Amount of experimental and clinical studies showed that acupunc--ture has clear curative effect and advantage in treating MI. Previous studies found that MI was closely related to calcium channel of cardiac muscle cell. However, study on the effect of acupuncture on calcium channel was rarely seen, and the passing mechanism of acupuncture is still been studied. So we observed the effect of acupuncture at Neiguan(PC6) on the expression of calcium channel protein expression in normal and gene knock-out mice and discuss the distinctive effect of acupuncture on calcium ion channel in MI as well as the passing mechanism of acupuncture, to reveal the characteristic of calcium channel of the heart in responding to acupuncture effects. Meanwhile, along with the increased pace of life and aggravated competitive pressure, incidence of MI induced or worsened by depression rose year by year. Since biology medical model is turning to biology-psychology-society model, the relevance of depression and MI is getting more and more attention. Existing studies showed tha depression can induce the incidence of MI through Hypothalamic-pituitaryadrenal(HPA) axis, and acupuncture can effectively treat depression, so we set up rats model of chronic stress depression(CSD) to imitate the pathological manifestation of depression in clinic. MI rats and MI combined with CSD rats were compared, and contents of HPA axis related index and expression of calcium channel protein were observed, to explore the relevance of CSD and MI and provide guidance for clinic.Materials and methods:1. In the experiment of effect of acupuncture on the expression of calcium channel protein, 24 wild C57BL/6 mice and 21 ASIC3-/- mice of the same strain were chosen and divided into 5 groups seperately and randomly, including: normal group、model group、PC6 group、LU7 group and nonacupoint group. MI model was set up by subcutaneous injection of isoprenaline(ISO)(20mg/kg). ST segment and T wave of ECG were observed before and after modeling as well as after acupuncture. Parameters of echocardiogram reflect systolic and diastolic functions were recorded, including: left ventricle internal diastolic diameter(LVIDd), left ventricular internal diameter at end-systole(LVIDs)、E/A、ejection fraction(EF)、 strokevolume(SV) and shortening fraction(FS). Morphological changes of myocardial tissue were observed under light microscope. Contents of CK-MB and LDH were tested by ELISA method. Expressions of calcium ion channel protein were tested by Western-blot, including: Cavα1C、Cavβ、Cavα2-δ1、Ca M and Ca MKII.2. In the experiment of relevance of CSD and MI, 50 SD rats were chosen and divided into 5 groups: normal group, MI group, MI combined with CSD group, PC6 treating 1 group(PC6 treating MI group) and PC6 treating 2 group(PC6 treating MI combined with CSD group). MI rat model was set up by subcutaneous injection of isoprenaline(ISO)(85mg/kg), MI combined with CSD rat model was set up by subcutaneous injection of isoprenaline(ISO)(85mg/kg) and forced restraint plus swimming. After treating with PC6, protein expression of CRH was tested by Western-blot, contents of ACTH and CORT were tested by ELISA and protein expression of calcium channel was tested by Western-blot, including: Cavα1C、Cavβ、Cavα2-δ1、Ca M and Ca MKII.Results:1. Besides the normal group, in the interior-group comparison, amplitude of ST segment and T wave of the other groups were elevated with different degrees, and heart rates were reduced in both C57BL/6 and ASIC3-/-rats after MI compare to that before MI. There was significant difference(P<0.01), which prove the successful modeling of MI. Amplitude of ST segment and T wave was reduced in PC6、LU7 and nonacupoint groups after acupuncture treatment compared to that after MI, there was significant differece(P<0.01). Amplitude of ST segment and T wave was reduced more significant in PC6 group compare with that of LU7 and nonacupoint groups, there was significant differece(P<0.01). After acupuncture, heart rate showed no significant changes in PC6、LU7 and nonacupoint groups, there was no significant differece(P>0.05). Compared with ASIC3-/-rats, amplitude of ST segment and T wave was decreased more significant in C57BL/6 rats group, there was significant differece(P<0.01).2. Besides the normal group, in the interior-group comparison, LVIDd and LVIDs of the other groups were elevated with different degrees, and E/A、EF、FS and SV were reduced in both C57BL/6 and ASIC3-/-rats after MI compare to that before MI. There was significant difference(P<0.01). LVIDd was reduced and E/A was elevated in PC6、LU7 and nonacupoint groups after acupuncture treatment compared to that after MI, there was significant differece(P<0.01). LVIDd was reduced more significant and E/A was elevated more significant in PC6 group compare with that of LU7 and nonacupoint groups, there was significant difference(P<0.01). Compared with ASIC3-/-rats, LVIDd was decreased more significant and E/A was elevated more significant in C57BL/6 rats group, there was significant differece(P<0.01). After acupuncture, LVIDs、EF、FS and SV value in PC6、LU7 and nonacupoint groups didn’t show significant improvement and there was no significant difference compared with that after modeling(P>0.05).3. After light microscope test, it was found that acupuncture at PC6、LU7 and nonacupoint had protective effect on cardiac muscle in both C57BL/6and ASIC3-/-rats, but PC6 had more significant effect.4. After MI, compared with normal group, there was increase of serum CK-MB and LDH content(P<0.01), which prove the successful modeling of MI. After MI, compared with normal group, protein expression of Cavα1c、Cavβ、Cavα2-δ1、Ca M and Ca MKII were increased in model group(P<0.01). Compared with model group, protein expression of Cavα1c、Cavβ、Cavα2-δ1、Ca M and Ca MKII were significantly decreased in PC6、LU7 and nonacupoint groups, there was significant differece(P<0.01). Compared with LU7 and nonacupoint groups, protein expression of Cavα1c、Cavβ、Cavα2-δ1、Ca M and Ca MKII decreased more significantly in PC6 group, there was significant differece(P<0.01). Compared with ASIC3-/-rats, protein expression of Cavα1c、Cavβ、Cavα2-δ1、Ca M and Ca MKII improved more significantly in C57BL/6 rats, there was significant differece(P<0.01).5. Compared with normal group、MI model group and PC6 treating 1 group, weight gain and sucrose intake of MI combined with CSD group and PC6 treating 2 group decreased, there was significant differece(P<0.01), indicating the successful modeling of CSD. At the 2nd、4th、7th day,compared with MI combined with CSD group, weight gain and sucrose intake of PC6 treating 2 group increased, there was significant differece(P<0.01), indicating acupuncture can improve weight gain and sucrose intake of MI combined with CSD rats. Compared with normal group, protein expression of CRH、serum content of ACTH and CORT, protein expression of Cavα1c、Cavβ、Cavα2-δ1、Ca M and Ca MKII increased in MI model group and MI combined with CSD model group, there was significant differece(P<0.01). Compared with MI model group, protein expression of CRH、serum content of ACTH and CORT, protein expression of Cavα1c、Cavβ、Cavα2-δ1、Ca M and Ca MKII increased in MI combined with CSD model group, there was significant differece(P<0.01), indicating that CSD could aggravate hyperfunction of HPA axis and increase of protein expression of calcium channel.After acupuncture at PC6, compared with MI model group, protein expression of Cavα1c、Cavβ、Cavα2-δ1、Ca M and Ca MKII decreased in PC6 treating 1 group, there was significant differece(P<0.01); compared with MI combined with CSD model group, protein expression of CRH、serum content of ACTH and CORT, protein expression of Cavα1c、Cavβ、Cavα2-δ1、Ca M and Ca MKII decreased in PC6 treating 2 group, there was significant differece(P<0.01), indicating that acupuncture at PC6 could improve the increase of CRH protein expression and serum content of ACTH and CORT, as well as inhibit the increase of rotein expression of Cavα1c、Cavβ、Cavα2-δ1、Ca M and Ca MKII.Conclusion:1. In MI, there was changes in ECG、echocardiogram、light microscope and protein expression of calcium channel and acupuncture could improve these index. It illustrated that acupuncture at PC6 had protective effect on cardiac cell, and the characteristic of calcium channel of the heart in responding to acupuncture effects is to improve the increase of protein expression of calcium channel to inhibit calcium overload.2. In MI, it showed changes of ECG、echocardiogram、light microscope and protein expression of calcium channel in both non-ASIC3-/-and ASIC3-/-rats, and acupuncture could improve the index of both 2 kinds rats. Acupuncture had more significant effect on non-ASIC3-/-rats than ASIC3-/-rats, indicating that passing mechanism is possibly by activating ASIC3 ion channel to inhibit sympathetic nerve and to treat MI.3. Protein expression of calcium channel in MI combined with CSD rats was more than in MI rats, which showed that CSD could aggravate MI damage and MI is closely related to CSD. Acupuncture at PC6 could improve the HPA hyperfunction and calcium channel expression of MI rats and MI combined with CSD rats, indicating that PC6 could treat MI as well as CSD. One acupoint could treat two disease at the same time indicates that MI is closely related to CSD in treatment.4. The above conclusions illustrate the theory of acupoint-Zang and Fu related, CSD-MI related, which provide theory basis for acupoint-Zang and Fu relevance and depression-MI relevance.