[Effects of Astragalus membranaceus and Potentilla discolor mixture on insulin resistance and its related mRNA expressions in KKAy mice with type 2 diabetes].

OBJECTIVE: To investigate the effects of Astragalus membranaceus and Potentilla discolor mixture (APM) on insulin resistance (IR) and mRNA expressions of IR-related genes, including phosphatidylinositol 3-kinase (PI3-K), phosphoenolpyruvate carboxykinase (PEPCK) and peroxisome proliferator-activated receptor γ coactivator 1 (PGC1) in KKAy mice with early type 2 diabetes and to explore the gene regulation mechanisms of AMP. METHODS: After giving short-term high-fat and high-calorie diet to induce type 2 diabetes, male KKAy mice were randomly divided into model and APM groups. Nine C57BL/6J mice were used as normal control in addition. The mice in the APM group were treated with 830 g/L of the APM liquid by gastric infusion while the mice in the model group and the normal control group were given 0.05% sodium carboxymethyl cellulose at a dose of 0.1 mL/g body weight once per day. After four weeks, fasting plasma glucose (FPG) was tested using tail vein blood. Fasting serum insulin (FINS) was tested by radioimmunoassay. Insulin sensitivity index (ISI) was calculated as the natural logarithm of the product of FPG and FINS. The mRNA expressions of PI3-K, PEPCK and PGC1 in liver tissues were tested by real-time fluorescence quantitative polymerase chain reaction assay. RESULTS: Both the levels of FPG and FINS in the model group and the APM group were increased, while the ISI values were decreased when compared to those of the normal control group (P<0.01). The level of FPG in the APM group was decreased, while ISI was increased when compared to those of the model group (P<0.05). All of the mRNA expressions of PI3-K, PEPCK, and PGC1 in liver tissue of the model group were decreased compared with the normal control group (P<0.01). The mRNA expressions of PI3-K and PGC1 in the liver tissue of the APM group were higher than those in the model group (P<0.05). CONCLUSION: APM can improve the insulin resistance of mice with type 2 diabetes. The mechanism may be related to increasing the mRNA expressions of PI3-K and PGC1 in the liver tissue.

[Effects of Chinese herbal medicines Shengmai injection and Xuesaitong injection on ventricular fibrillation threshold and connexin 43 expression in rats with myocardial infarction].

OBJECTIVE: To explore the effects of Shengmai injection and Xuesaitong injection, compound Chinese herbal medicines for replenishing qi and activating blood, on ventricular fibrillation threshold, heart structure and connexin 43 (Cx43) expression in rats with myocardial infarction (MI). METHODS: One hundred male SD rats were randomly divided into sham operation group, model group, Yiqi Huoxue (YQHX) group (Shengmai injection plus Xuesaitong injection) and captopril group. MI model of rats was established by ligating left anterior descending coronary artery, and rats in sham operation group were prepared in the same way except for the ligation of coronary artery. Rats were treated with corresponding drugs for 1 month from next day after modeling. After treatment ventricular fibrillation threshold was detected, and heart weight index, left ventricular internal diameter and percentage of myocardial infarction were measured. Expression of Cx43 mRNA in myocardium was detected by real-time fluorescent quantitative polymerase chain reaction, and expression of Cx43 protein was observed by immunohistochemical method. RESULTS: Compared with the sham operation group, ventricular fibrillation threshold decreased significantly, heart weight index and left ventricular internal diameter increased, while expressions of Cx43 mRNA and protein decreased remarkably in the model group (P<0.01). Compared with the model group, ventricular fibrillation threshold was increased significantly, heart weight index, left ventricular internal diameter and percentage of myocardial infarction were decreased significantly in the YQHX group and captopril group (P<0.05 or P<0.01). When it comes to expression of Cx43, both Cx43 mRNA and protein expressions were increased remarkably in the YQHX group compared with the model group (P<0.05 or P<0.01), while only density mean and integral optical density of Cx43 protein expression were increased significantly in the captopril group (P<0.05). The enhancements on Cx43 mRNA and positive area sum of Cx43 protein induced by YQHX drugs were stronger than those induced by captopril (P<0.05). CONCLUSION: Shengmai injection and Xuesaitong injection have beneficial effects on ventricular fibrillation threshold in rats with MI. The mechanism is related with improving heart structure and reducing Cx43 expression after MI.

[Effects of tetramethylpyrazine on angiotensin II -induced proliferation and type I collagen synthesis of rat cardiac fibroblasts].

OBJECTIVE: To observe the effects of tetramethylpyrazine (TMP) on the proliferation and type I collagen synthesis of rat cardiac fibroblasts (CFBs) induced by angiotensin II (Ang II), and to explore the mechanism of TMP in treating myocardial fibrosis. METHODS: CFBs were isolated from neonatal rats, and the fourth-passage CFBs were used in the entire test and were stimulated by 0.1 micromol/L Ang II in vivo. The CFB proliferation was measured by methyl thiazolyl tetrazolium (MTT) assay. Type I collagen in the cell culture supernatant was measured by enzyme-linked immunosorbent assay. The expression of mRNA of type I collagen was semi-quantitatively measured by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: (1) In MTT assay, the optical density of CFBs cultured with 0.1 micromol/L Ang II was higher than that of the blank control cultured with 2% fetal bovine serum-Dulbecco's modified Eagle's medium (FBS-DMEM). The difference was statistically significant (P < 0.05). Both optical densities of CFBs cultured with 0.1 micromol/L Ang II plus 800 microg/mL TMP and 0.1 micromol/L Ang II plus 600 microg/mL TMP were lower than that of CFBs cultured with 0.1 micromol/L Ang II, but only the difference between 0.1 micromol/L AngII plus 800 microg/mL TMP group and 0.1 micromol/L Ang II group was significant (P < 0.05). (2) The content of type I collagen secreted by CFBs cultured with 0.1 micromol/L Ang II was higher than that with 2% FBS-DMEM (P < 0.01). The content of type I collagen secreted by CFBs cultured with 0.1 micromol/L Ang II plus 800 microg/mL TMP was lower than that with 0.1 micromol/L Ang II (P < 0.05). (3) The level of type I collagen mRNA in 0.1 micromol/L Ang II group was higher than that in blank control group, and lower than that in 0.1 micromol/L Ang II plus 800 microg/mL TMP group. Both the differences between 0.1 micromol/L Ang II group and the blank control group and between 0.1 micromol/L Ang II group and 0.1 micromol/L Ang II plus 800 microg/mL TMP group were statistically significant (P < 0.05). CONCLUSION: TMP can not only inhibit the proliferation of CFBs, but also decrease the secretion and the mRNA expression level of collagen I in cultured CFBs of rat which are increased by Ang II.

[Comparative study on early application of the recipe for activating blood circulation and the recipe for supplementing qi for inhibiting left ventricular remodeling and apoptosis in rats with heart failure].

OBJECTIVE: To compare the characteristics of early application of the recipe for activating blood circulation and the recipe for supplementing qi for inhibiting left ventricular remodeling and apoptosis in rats with heart failure. METHOD: The left coronary artery occlusion was conducted to establish the rat model of heart failure after myocardial infarction. The model rats were randomly divided into 5 groups, including model group, activating blood circulation group (8 g x kg(-1)), supplementing qi group (8 g x kg(-1)), activating blood circulation plus supplementing qi group (16 g x kg(-1)), and captopril group (10.125 g x kg(-1)), and a sham operation group was set up as negative control group. The drugs were administrated on the second day after myocardial infarction with a therapeutic course of 4 weeks or 8 weeks. The heart function was detected by impedance method; Pathological staining and image analysis were used to determine the perimeter and the area of left ventricular cavity, and myocardial nuclei number and collagen content per unit area; Apoptosis percentage of the myocardial cell was detected by TUNEL and the content of Ang II in the cardiac muscle was measured by radioimmunoassay. RESULT: In comparison with the model group, the function of left ventricular contraction function improved, the area of left ventricular cavity diminished, and proliferation of collagen, content of Ang II and apoptosis percentage of the myocardial cell reduced in all of the treatment groups (P < 0.05 or P < 0.01). After treatment of 8 weeks, the activating blood circulation group was similar to the sham operation group in improvement of cardiac index, and decreases of the area of left ventricular cavity and the content of Ang II; Apoptosis percentage of the myocardial cell in the activating blood circulation group was significantly lower than that in the supplementing qi group. CONCLUSION: Both the recipes for activating blood circulation and for supplementing qi can inhibit left ventricular remodeling and myocardial apoptosis, and delay development of heart failure, with the best effect in the activating blood circulation group after treatment of 8 weeks.

[Study on cardiac gene expression microarray and recipe for activating blood circulation and supplementing qi on heart of rats with post-infarction heart failure].

OBJECTIVE: To observe the effect of recipe for activating blood circulation and supplementing Qi (RAS) on cardiac functional structure in rats with post-infarction heart failure (PIHF). METHODS: Rat model of PIHF was established by left coronary artery ligation. Left ventricular samples of model rats from infarcted or peri-infarcted area were obtained at PIHF formation stage and stable stage (10 days and 8 weeks respectively after operation), the total RNA extracted and detected using 6 pieces of rat's 40s gene microarray (4096 genes/microarray), the data were analyzed using software as Genespring, Treeview, Clustering and SOM. Besides, RAS was used to treat the model rats beginning from 4 weeks after modeling and lasted for 4 weeks, changes of heart function and cardiac coefficient before and after treatment were observed by impedance method with Captopril as positive control. RESULTS: (1) Genespring analysis showed thousands of genes differential expression (upper or down regulated), including 13 kinds of gene involving energy metabolism, myocardial cytoskeleton, fibrosis, etc. which, in the infarcted area at heart formation stage were 1086 genes and at the stable stage, 724 genes, while in the peri-infarcted area, formation stage 196 genes and stable stage 97 genes. (2) After RAS or Captopril treatment, the heart function improved significantly, with the stroke volume, cardiac output and cardiac index increased significantly (P < 0.01). RAS could also improve the cardiac coefficient of model rats, as compared with that in untreated model, P < 0.01, compared with that in the sham-operated rats, P < 0.05. CONCLUSION: PIHF is a kind of overload heart disease with multiple genes abnormality. RAS could improve the heart function and histologic indexes, so as to treat the heart failure.

[Effect of different drug dosage to activate blood circulation and to nourish qi on cardiac function and structure of congestive heart failure rats after acute myocardial infarction].

OBJECTIVE: To observe the effect of different drug dosage to activate blood circulation and to nourish Qi on cardiac function and structure of heart failure rats after acute myocardial infarction. METHOD: The congestive heart failure post cardiac infarction rats models subjected to left coronary occlusion were made and given different dosage of drug of Huoxue Yiqi and captopril (positive control) from 4 weeks to 8 weeks after operation. The cardiac function before and after using drugs were observed by impedance methods. RESULT: Treated by different dosage of drug of Huoxue Yiqi and captopil, cardiac function of heart failure rats after acute myocardial infarction improved, SV, CO, CI(P < 0.01); at the same time, prescription of Huoxue Yiqi and Qixue could improve the model rats' heart coefficient, VS SHAM(P > 0.05), but prescription of Yiqi Huoxue and captopril could not improve it. CONCLUSION: Drug to activate blood circulation and to increase qi can treat heart failure rats after acute myocardial infarction, through improving their function and structure. At the same time, more dosage of drug to activate blood circulation and to increase qi(Huoxue/Yiqi drug) may improve the model rats' heart coefficient.