Study on the Relationship between Cardiomyocyte Apoptosis and Left Ventricular Function in Spontaneously Hypertensive Rats

Abstract

At present, hypertension is a relatively common cardiovascular disease. It not only affects the normal operation of target organs such as the heart and kidneys, but also causes cardiovascular and cerebrovascular diseases, which can lead to death. The apoptosis of cardiomyocytes is widespread in the cardiovascular system and is closely related to vascular diseases. Therefore, the purpose of this article is to explore the relationship between changes in left ventricular function, myocardial multidimensional strain and interstitial fibrosis in spontaneously hypertensive rats (SHR) during cardiomyocyte apoptosis. Whether the research is consistent in terms of order, as the age of hypertensive rats increases, whether there is a close connection between myocardial cell apoptosis and the structure and function of the left heart. The method in this article is to use the method of experimental comparison to randomly group 60 experimental mice and observe the changes of various indicators of rats of different ages, from 12 weeks to 84 weeks. The observations include left ventricular mass index (LVMI), left ventricular ejection fraction (LVEF), left ventricular short axis shortening rate (FS), LVEDP, LV+dp/dtmax, LV-dp/dtmax. At the same time, using the TUNEL labeling method, the left ventricular myocardial tissue was sliced, and the apoptosis index of subendocardial and subepicardial myocardial cells was calculated. Then 3 groups were randomly selected from the experimental group, and Western blotting was used to quantitatively detect apoptosis-related the expression of the proteins Bcl-2, Bax, and Fas were compared between the groups. After analysis and determination, it can be found that the apoptosis index of cardiomyocytes is positively correlated with LVMI, CVF, and PVCA (r is 0.83, 0.89, 0.72, respectively, p=0.00). Corresponding conclusions are drawn from the comparison of data. As hypertensive rats grow older, the apoptotic index of cardiomyocytes will continue to increase, and when the myocardial hypertrophy is severe to heart failure, the apoptotic index of cardiomyocytes will increase significantly. This shows that the increase in cardiomyocyte apoptosis is closely related to left heart remodeling, the development of myocardial fibrosis and overall cardiac dysfunction.