Effects Of Ligustrazine Injection On The Protection Of Diabetic Cardiomyopathy Induced By Steptozotocin

Ligustrazine is a Chinese herbal medicine and widely used to treat cerebral, pneumonic,renal and cardiovascular diseases.And recently,more and more research showed that Ligustrazine exerted its protection in diabetes by through oppositing the injury of oxygen free radicals,preventing the inflowing of calcium ion and protecting the texture of macrophage membrane,et al.But little is known about the protection effect of Ligustrazine on the diabetic cardiomyopathy.In this study,we will elucidate the exact mechanism of Ligustrazine on diabetic cardiomyopathy by using morphology,immunohistochemistry and patch clamp methods.1.The establishment of diabetic cardiomyopathy modelObjective:To observe the injury of cardiac muscle tissue of the diabetic cardiomyopathy induced by STZ and the effect of protecting of ligustrazine to this injured cardiac muscle tissue.Method:8 SD rats choosed at random make up of the sham group and the rest of rats make up of the model group.All of the rats were fed with normal feedstuff for one week and then were not permitted to eat anything for 12 hours.In model group,55 mg/kg STZ (dissolved in 0.1 mmol/L Sodium Citrate,pH 4.5)was injected in abdominal cavity,and the same volume of Sodium Citrate was injected in sham group.And then,24 SD rats of diabetic cardiomyopathy choosed from the model group were divided into three groups. They are the model group,the group of large quantity of ligustrazine and the group of small quantity of ligustrazine.The new three groups and the sham group were injected different medicine for 8 weeks respectively.Using the methods of morphology,pathological section and measuring the weight and the blood sugar,we observe the injury of cardiac muscle tissue of the diabetic cardiomyopathy induced by STZ and the effect of protecting of Ligustrazine to this injured cardiac muscle tissue.Result:The diabetes rats showed that polyphagia,polydipsia,polyuria and emaciated, growing slowly etc.The weight and blood sugar of the model group are higher than those in sham group remarkably(P＜0.01).The result of the pathological section showed that the myocardial cells of the model group are hypertrophic and swollen and they lines up chaosly etc.The degree of the myocardial cells injury in the groups of large and small quantity of ligustrazine is lower than that in the model group.Conclusion:we established the diabetic cardiomyopathy model in rats by using injuction of large quantity of STZ in abdominal cavity successfully.The ligustrazine could protect cardiac muscle tissue of diabetic cardiomyopathy to some extent.2.Effects of ligustrazine on TGF-β₁ of the cardiac muscle tissue in the diabetic cardiomyopathyObjective:To observe the effects of the different concentration of ligustrazine on TGF-β₁ of the cardiac muscle tissue in the diabetic cardiomyopathyMethod:The methods of establishing diabetic cardiomyopathy model in rats and the grouping are the same.Using the SABC staining method of immunohistochemistry,we detect the effects of the different concentration of ligustrazine on TGF-β₁ of the cardiac muscle tissue in the diabetic cardiomyopathy rats.Result:The result of image analysis show that the positive area rates of TGF-β₁ in the model group,the sham group,the group of large quantity of ligustrazine and the group of small quantity of ligustrazine are 2.888,0.405,0.912 and 1.935 respectively.The positive area rate of TGF-β₁ in the model group is higher than that in the sham group remarkably ((P＜0.05).The positive area rates of TGF-β₁ in the group of large quantity of ligustrazine and the group of small quantity of ligustrazine are lower than that in the model group remarkably(P＜0.001).The difference between the group of large quantity of ligustrazine and the small quantity of ligustrazine is remarkably too(P＜0.05),and the effect of the large quantity of ligustrazine is better than that of the small quantity of ligustrazine for the diabetic cardiomyopathy rats.Conclusion:Ligustrazine is able to reduce the TGF-β₁'s content of the cardiac muscle tissue in the diabetic cardiomyopathy.And the effect of the large quantity of ligustrazine is better than that of the small quantity of ligustrazine for the diabetic cardiomyopathy rats.3.Effects of ligustrazine on collagenâ…¢of the cardiac muscle tissue in the diabetic cardiomyopathyObjective:To observe the effects of the different concentration of ligustrazine on collagenâ…¢of the cardiac muscle tissue in the diabetic cardiomyopathy.Method:The methods of establishing diabetic cardiomyopathy rats model and the grouping are the same as the first part.The empirical method is the same as the second part,we detect the effects of the different concentration of ligustrazine on collagenâ…¢of the cardiac muscle tissue in the diabetic cardiomyopathy.Result:The result of image analysis show that he positive area rates of collagenâ…¢in the model group,the sham group,the group of large quantity of ligustrazine and the group of small quantity of ligustrazine are 4.386,0.424,1.068 and 1.259 respectively.The positive area rate of collagenâ…¢in the model group is higher than that of in the sham group remarkably((P＜0.01).The positive area rates of collagenâ…¢in the group of large quantity of ligustrazine and the group of small quantity of ligustrazine are all lower than it in the model group remarkably(P＜0.05).Conclusions:Ligustrazine is able to reduce the collagen III's content of the cardiac muscle tissue in the diabetic cardiomyopathy rats.4.Effects of ligustrazine on[Ca²⁺]_i of the myocardial cell in the diabetic cardiomyopathyObjective:To observe the effects of different concentration of ligustrazine on[Ca²⁺]_i of the myocardial cell in the diabetic cardiomyopathy rats.Method:The methods of the establishing diabetic cardiomyopathy model in rats and the grouping are the same as the first part.After the myocardial cells of the diabetic cardiomyopathy rats are segregated acutely,we record the effects of the different concentration of ligustrazine on[Ca²⁺]_i of the myocardial cell in the diabetic cardiomyopathy rats with the method of image analysis of ion.Result:The[Ca²⁺]_i in the myocardial cell in the model group is higher than that in the sham group remarkably((P＜0.05).The[Ca²⁺]_i in the myocardial cell in the group of large quantity of ligustrazine and the group of small quantity of ligustrazine are all lower than it in the model group remarkably(P＜0.05).Conclusions:Ligustrazine is able to reduce the[Ca²⁺]_i in the myocardial cell of the diabetic cardiomyopathy rats.5.Effects of ligustrazine on L-type Calcium Channel of the myocardial cell in the diabetic cardiomyopathy rats Objective:To observe the effects of the different concentration of ligustrazine on L-type Calcium Channel of the myocardial cell in the diabetic cardiomyopathy.Method:The methods of the establishing diabetic cardiomyopathy model in rats and the grouping are the same as the first part.After the myocardial cells of the diabetic cardiomyopathy rats are segregated acutely,we record the effects of the different concentration of ligustrazine on the L-type Calcium ion's activity of the myocardial cell in the diabetic cardiomyopathy rats with the technique of patch clamp holding on the same voltage.Result:The opening time of L-type Calcium Channel in the myocardial cell in the model group is higher than that in the sham group remarkably((P＜0.05).The opening time of L-type Calcium Channel in the myocardial cell in the group of large quantity of ligustrazine and the group of small quantity of ligustrazine are shorter than that in the model group remarkably(P＜0.05)and are still longer than that in the sham group(P＜0.05). The electric current amplitude of L-type Calcium Channel in the myocardial cell in the model group is higher than that in the sham group remarkably((P＜0.05).The electric current amplitude of L-type Calcium Channel in the myocardial cell in the group of large quantity of ligustrazine is shorter than that in the model group remarkably(P＜0.05).The electric current amplitude of L-type Calcium Channel in the myocardial cell in the group of small quantity of ligustrazine has no difference with it of the model group(P＜0.05).Conclusions:Ligustrazine is able to shorten the opening time of L-type Calcium Channel in the myocardial cell of the diabetic cardiomyopathy rats.Ligustrazine is able to reduce the electric current amplitude of L-type Calcium Channel in the myocardial cell of the diabetic cardiomyopathy rats also.Summarized from above five experiments,the following conclusion could be derived: in the diabetic cardiomyopathy,Ligustrazine is able to reduce the TGF-β₁ and collagen III's content in cardiac muscle tissue.Ligustrazine is able to shorten the opening time of L-type Calcium Channel and reduce the[Ca²⁺]_i in the myocardial cell of the diabetic cardiomyopathy rats,which can protect myocardial cell.