MORPHOMETRIC ASSESSMENT CHANGES OF CERTAIN RETRACTIVE CARDIOMYOCYTES ULTRASTRUCTURES OF RIGHT VENTRICLE OF COR PULMONALE

Abstract

A hypertension in the small circle of circulation quite often meets in a clinic to which operations leads also on lungs (pulmonectomy, lobectomy). Pulmonary hypertension causes a hyperfunction and hypertrophy of right chambers of heart (a compensatory cor pulmonale) with next development of its decompensation. Until now debatable are questions about prevalence of cor pulmonale at pulmonary hypertension, role its in pathogenesis of this pathology and decompensation cor pulmonale.

The aim of the study – a quantitative morphological study of changes of some ultrastructures of retractive cardiomyocytes of right ventricle of cor pulmonale.

Materials and Methods. Retractive cardiomyocytes of right ventricle of heart researched morphological methods 22 white rats which were divided on 3 groups: a first group included 6 intact animals (control), second – 11 rats with arterial hypertension in the small circle of circulation and compensatory cor pulmonale, third – 5 animals with a pulmonary hypertension and decompensatory cor pulmonale. A pulmonary hypertension and cor pulmonale modeled of right pulmonectomy. Euthanasia of rats was carried out bloodlettings in the conditions of tiopental anesthesia in 3 months from the beginning of experiment. A heart was cut after the method of H. H. Avtandilov, conducted the separate weighing and planimetry of chambers of the heart. Carried out parts of right ventricle the generally accepted methods, prepared blocks for making of ultrathin cuts which after the proper treatment are examined in the electron microscope. Morphometric in cardiomyocytes of right ventricle did determine at the relative volume mitochondries and myofibrils, mitochondry-myofibrillar index, amount of mitochondries and сristа in mitochondria, area of mitochondria, amount of сristа and areas of mitochondries in electronogramm, coefficient of power efficiency of mitochondries (KEEM ). Quantitative indicators were treated statistically.

Results and Discussion. A separate weighing and planimetry of chambers of heart found that 3 months after right pulmonectomy mass and spatial characteristics of chambers of heart grew with prevailing of hypertrophy and dilatation of right ventricle. The results showed the development of cor pulmonale. In cardiomyocytes of right ventricle of the compensatory cor pulmonale the amount of сristа in mitochondria statistically for certain (p<0.01) grew on 6.3 %, area of mitochondria – in 1.38 times, sum of areas of mitochondries – in 1.3 times. Relative volume mitochondries did not almost change, and relative volume myofibrils grew on 20.4 %, mitochondrymyofibrillar index diminished on 15.0 %, that testified to unbalanced between power and retractive structures, that showed about dysfunction of retractive cardiomyocytes. In cardiomyocytes of right ventricle of decompensatory of cor pulmonale destructive processes increase, their power efficiency gets worse, there is disorganization and instability of subcellular structural homoeostasis.

Conclusions. Quantitative morphological methods were established, that in retractive cardiomyocytes of right ventricle of the compensatory cor pulmonale there is growth area of mitochondries, amount of their crista and coefficient them power efficiency. During decompensation of cor pulmonale in retractive cardiomyocytes of right ventricle their ensuring of energy gets worse expressed which is characterized the substantial diminishing of amount of mitochondries, their crista and coefficient of power efficiency of mitochondries.