SPECIFICS OF THE STATE OF MYOCARDIUM AND PROFIBROTIC FACTORS IN THE DEVELOPMENT OF HYPERTENSIVE HEART

Introduction. Myocardial damage caused by arterial hypertension is manifested by changes in myocardial geometry and mass, as well as increased content of collagen and fibrous tissue in the myocardium. Excessive accumulation of collagen in myocardium is the result of imbalance between proteolytic enzymes such as matrix metalloproteinases 1 (MMP-1) and tissue inhibitors of matrix metalloproteinase 1 (TIMMP-1), high content of transforming growth factor β1 (TFG-β1), which was found in fibroblasts and macrophages. Aim. The aim of the study was to investigate the role of MMP-1 activation, its tissue inhibitor TIMMP-1 and TGF-β1 in blood in the development of myocardial fibrosis in locomotive train workers with arterial hypertension. Material and methods. 82 patients with arterial hypertension and 20 virtually healthy control subjects were examined. The patients of the analyzed groups underwent evaluation of the data of daily blood pressure monitoring, echocardiographic examination, based on which the types of left ventricular remodeling, the content of matrix metalloproteinase 1 and its tissue inhibitor activity, the level of transforming growth factor β1 in blood serum were identified. Calculation of the volume fraction of interstitial collagen was performed. Results and discussion. The study established statistically significant signs of structural changes in the left ventricular myocardium, which primarily indicated its marked left ventricular hypertrophy against the background of arterial hypertension due to chronic pressure overload. Statistically significant increase of all levels of serum markers of collagen metabolism was revealed in patients with arterial hypertension in comparison with the control group. Patients with arterial hypertension have a restructuring of the intercellular matrix components and imbalance in the MMP-1/TIMMP-1 system characterized by a shift of the collagen balance towards fibrosis (increase of THF-β1, TIMMP-1 level, decrease of MMP-1/TIMMP-1 52 ВЕСТНИК СОВРЕМЕННОЙ КЛИНИЧЕСКОЙ МЕДИЦИНЫ 2021 Том 14, вып. 6ОРИГИНАЛЬНЫЕ ИССЛЕДОВАНИЯ ratio and increase of interstitial collagen volume fraction). Significant increase of interstitial collagen volume fraction index in the group of patients with arterial hypertension comparing to the control group also indirectly indicates high intensity of interstitial collagen genesis in myocardium of these patients. Conclusion. In arterial hypertension, serum levels of THF-β1, MMP-1, and TIMMP-1 increase, which indirectly indicates an increase in myocardial collagen content.