Effects Of Acupoints Electroacupuncture On The Expression Of MMP-2and MyHC-Ⅰ In Mascticatory Muscle Of Rat With Mandibularp Rotrusion

Objective: To compare different expression of matrixmetalloproteinase-2(MMP-2) and myosin heavy chain Ⅰ(MyHC-Ⅰ) inmasticatory muscles of rats at different periods between acupointselectroacupuncture stimulating mandibular protrusion and just mandibularprotrusion.Observe acupoints electroacupuncture can or not promotealterations of masticatory muscles in the process of functionaltreatment.Try to provide the basis for acupoints electroacupuncture as anadjuvant therapy of functional treatment.Methods: five weeks old,male SD rats were selected as experimentalanimals. First, SD rats were divided into three groups.frequency2/5HZ,2/15HZ,2/100HZ, observe the difference of muscle contraction force.Second, seventy-two rats randomly divided into three groups:the blankgroup,the conditional group,the experiment group.Each group wereselected six rats killed at3d、7d、14d、21d，The immunohistochemistryand FQ-PCR methods are used to find expression and differences ofMMP-2and MyHC-I protein and mRNA in the masticatory muscle of growing rats.Results：①muscle contraction force is the largest at the frequency of2/5HZ.②compared with the conditional control group, the expression ofMMP-2in experimental group is significantly increased at3d.7d,withstatistical difference(P<0.05),at21d,the expression of MMP-2isdecreased, with statistical difference(P<0.05). compared with theconditional control group,the expression of MyHC-Ⅰ in experimentalgroup is significantly increased at3d.7d.14d. with statisticaldifference(P<0.05),at21d, there is no difference.③the result of FQ-PCR isas same as the result of immunohistochemistryConclusion:①2/5HZ is the optical frequency.②EA can up regulatethe expression of MMP-2and MyHC-Ⅰ in masticatory muscle of rats withmandibular protrusion,has the possibility to be an adjuvant therapy offunctional treatment.