Study On The Mitochondrial Function Of Smooth Musclecells In Spontaneously Hypertensive Rats

Background: Essential hypertension (EH) is one of the most common humancardiovascular disease, is also an important risk factor for heart failure,coronary heartdisease,stroke and so on,and seriously affects human health and life. Currently, anumber of studies (2,6) show that mitochondrial DNA (mtDNA) mutations correlatedwith the incidence of hypertension, which is maternal inheritance. Some studies showthat mtDNA mutations may affect blood pressure by altering the synthesis ofmitochondrial energy, reactive oxygen species (ROS) generation and calciumhomeostasis. what is a relationship between mitochondrial function and EH, and isthere any changes in mitochondrial function in hypertension, which will provide astrong theoretical basis for the human mitochondrial function in studying thepathogenesis of hypertension.Objective: To study the changes of mitochondrial function in spontaneouslyhypertensive rats aortic smooth muscle cells (VSMCs).Method:（1）Take19-20weeks male spontaneously hypertensive rats (SHR) andcorresponding ages of normal rats (WKY), cultured VSMCs by adherenting,take the3rd generation of stable cell as the research object.（2）To study morphologicalchanges between hypertension group and normal group of cells by microscope,toassay cellular ATP levels by using of the fluorescence and to detect ROS andmitochondrial membrane potential of cells by flow cytometry.（3）Take106cells toextract RNA, and to detect the expression of mRNA about ND1,ND2, CYTB, ATP8and CO1in mitochondrial respiratory chain by real-time PCR.Results:1.The state of the normal rat VSMCs is better than the hypertension ratVSMCs by optical microscope under the same condition.2. The cultured cells are identified as VSMCs by immunocytochemistry, and it has agood purity.3. ATP generation in hypertensive rat group is51.581±3.280nmol/L, the normal ratgroup60.873±2.750nmol/L. Compared with the control group, the hypertensive group significantly reduced (n=6, P <0.01); The ROS of hypertensive group (1.082±0.146) is increased significantly compared with the normal group (0.752±0.043)(n=6, P <0.01); The mitochondrial membrane potential of hypertensive group(1.401±0.132) compared with the normal group (1.614±0.173) was significantlylow (n=6, P <0.01).4. The expression of ND1mRNA in the hypertensive group (0.488±0.055) wassignificantly lower than the normal group (1.000, P<0.01);The expression ofhypertensive ND2mRNA (0.907±0.253) and normal ND2mRNA (1.000) is nosignificantly different; The expression of the respiratory chain complex III CytbmRNA in the hypertensive group (0.955±0.232) is almost same to normal controlgroup (1.000); The expression of respiratory chain complex IV CO1mRNA (1.247±0.289) and the respiratory chain complex V ATP8(1.167±0.283) is both increasedin the hypertensive group,but there was no statistically significant difference.Conclusion:1. Mitochondria function significantly affected by the high blood pressure,especially in some indicators that mitochondrial function (such as cell state, ATPlevels, ROS, mitochondrial membrane potential, etc.).2. The mutations of ND1may be associated with hypertension, which leads to changein mitochondrial function.