OBJECTIVETo study pathological and therapeutical problems concerning myocardial cell mitochondria changes during myocardial cell hypertrophy by culturing rat primary myocardial cells.

METHODPrimary myocardial cells were seperated and cultured together with angiotensin II (Ang II) for 72 or 96 hours. The total protein content with the BCA method and the photography and measurement of cell diameter with inverted microscope reflected myocardial cell proliferation. The mitochondrial membrane potential (Delta Psi m) with fluorescence microscope, the mitochondrial single amine oxidase (MAO) activity with spectrophotometer, the mitochondrial cytochrome oxidase (COX) activity and the injury percentage of mitochondrial outer membrane with microplate reader and the contents of ATP, ADP, AMP with high performance liquid chromatography reflected the injury and energy metabolism of myocardial cell mitochondrial structure and function when being cultured together with Ang II. On that basis, cells were treated with Astragali Radix injection and valsartan for observing pharmacological effects on mitochondrial structure and function in restructured myocardial cells.

RESULTIn 72 h and 96 h, compare with the control group, the model group showed significantly increased total protein content and enlarged myocardial cell diameter. During the course of proliferation, the myocardial cell MAO activity and the injury percentage of mitochondrial outer membrane were significantly increased, with significant decrease in mitochondrial COX activity, mitochondrial Delta Psi m and the content of ATP, ADP and rise in the content of AMP. Astragali Radix injection and valsartan reduced myocardial cell total protein content and cell diameter caused by Ang II, decreased myocardial cell MAO activity, significantly increased mitochondrial COX activity and the content of ATP and ADP, and decreased the content of AMP.

CONCLUSIONDuring the process of myocardial hypertrophy, the injury of mitochondrial structure and function and the changes in myocardial cell energy metabolism injury occurred after the injury of mitochondria. Astragali Radix injection and valsartan can reverse myocardial cell mitochondrial structure and function during myocardial cell hypertrophy caused by Ang II. Reversion of myocardial cell hypertrophy and restructuring of myocardial cells helps improve energy metabolism of the myocardial cells.