Effects Of Acupuncture At "Neiguan" And "Shenmen"Points On ANP And NPR-A In The Heart Of Rat Model With Anxiety

Objective:This study is supposed to explore the effects of acupuncture at "Neiguan","Shenmen" points of chronic unexpected stress anxiety rat model and to observe the change of ANP, NPR-A and the expression, so as to reveal the mechanism of acupuncture in treating the anxiety disorder and supply the available experimental explanation for "tranqulizing the heart" theory about the therapeutic rationale of tranquilizing heart and calming mind for anxiety disorders.Methods:The male SD rats were stochastically seperated the animals into3groups, the blank untreated group, the stress model one and the acupuncture therapy one according to the weight. Model and acupuncture groups were both stimulated by chronic unpredictable stress for15days. Penetrating at "Neiguan" and "Shenmen" of one side, alternately stimulating the points of the left and right side every other day, the treatment course lasted for8days. Using electric acupuncture, with dilatational wave, and the voltage of1to3v as well as the recurrence rate about15to25Hz, the points were stimulated for15min per time. Estimate the anxiety-like behavior by observing the EPM and open field results. Determine the atrial ANP and NPR-A through the immunohistochemical method, and detect the atrial NPR-A mRNA using hybridization in situ, and examine the plasma ANP by RIA means.Results:1. The anxiety model activity results:(1) EPM detection indicators showed:model group OE%value were significantly reduced when comparing with the blank one, P<0.05, demonstrating the modeling was successful; relatively to model one, acupuncture group OT%data was significantly up-regulated, P<0.05, confirmed that acupuncture might antagonize anxiety. Although significant OT%value change was not found, the trend was similar to OE%.(2) Open boxes experimental data trend proved:vertical motion data of model group became slightly lower than blank one, while acupuncture group slightly elevated than model group, indicating that the model were successful and acupuncture can antagonize anxiety to a certain extent; whereas the horizontal movement data showed the opposite trend. And the results of acupuncture group were both closer to the blank group.2. Plasma ANP concentration:Compared to the blank group, the models’ ANP concentrations increased in evidence(P<0.05), suggesting that in the2nd week after modeling, ANP secretion in model group seemed excited in a certain degree.When comparing with the model group, ANP concentration in acupuncture group were down-regulated (P<0.05) and closer to the blank group,which indicated that ANP secretion in the models of anxiety increased to a certain extent, and acupuncture might down-regulate the increased ANP.3. atrial ANP relevant indicator results:(1) ANP levels:①in the right atrium:comparing with blank group, the ANP optical density of models up-regulated in evidence (P<0.05), whereas the acupuncture one significantly decreased than model one(P<0.01), showing that the chronic unpredictable anxiety modeling method might promote ANP production in the rats’ right atrial tissue, and acupuncture decreased,and there was no difference in the three groups.②in the left atrium:when comparing with the blank untreated one,the ANP optical density in the acupuncture group was elevated and the acupuncture one changed significantly(P<0.01), confirmed that left atrial ANP rise were not currently affected by acupuncture.(2) the level of atrial NPR-A:①in the right atrium:no obvious change were seen;②in the left atrium:compared to the blank one, the model group’s optical density value increased; while the acupuncture group’s NPR-A showed an decreasing tendency when comparing with the model one (P<0.05), suggesting the acupuncture’s inhibition effect on left atrium NPR-A.(3) the atrial NPR-A mRNA level:①in the right atrium, the acupuncture therapy group’s NPR-AmRNA became significantly down-regulated than model’s (P<0.01), because that acupuncture has some effect on the right atrial NPR-AmRNA expression;②in the left atrium,NPR-A mRNA expression of the model group became significantly higher than blank one (P<0.01), while the data of acupuncture group became lower than the stress model one(P<0.05), and the acupuncture group expression value was close to the blank one, indicating the acupuncture’s suppression role in NPR-A mRNA expression.Conclusion:Needling "Neiguan","Shenmen" points of chronic stress anxiety rat models showed acupuncture’s anxiolytic effects to a certain extent.And the intervention in atrial ANP generation and excretion as well as the according atrial receptor and gene expression might be the better explanation for acupuncture’s function of "tranquilizing the heart".