CHARACTERISTICS OF THE INTERSTITIAL COMPONENT IN THE VENTRICULAR MYOCARDIUM OF FETAL AND NEWBORN RATS FROM PHYSIOLOGICAL PREGNANCIES

• Published in: Актуальні проблеми сучасної медицини Вісник Української медичної стоматологічної академії Vol. 25; no. 2; pp. 170 - 174
• Main Authors: Sorokina, I.V., Kaluzhyna, O.V., Pliten, O.M., Markovskyi, V.D.
• Format: Journal Article
• Language: English
• Published: 29.05.2025
• ISSN: 2077-1096; 2077-1126; 2077-1126
• DOI: 10.31718/2077-1096.25.2.170

Objectives. To determine the morphological features of the interstitial component of the ventricular myocardium of fetal and newborn rats from physiological pregnancy using an experimental model. Material and methods. Ten hearts of fetuses, one-day-old and seven-day-old newborns from physiological pregnancy were investigated by applying histological and immunohistochemical methods (indirect Koons method with monoclonal antibodies to collagens of types I, III and IV). The optical density of collagen immunofluorescence was measured. The average values of the indicators in the groups were compared using the Student t-test and the Mann-Whitney U-test. The significance of the differences between the indicators was accepted at a significance level of <0.05. Results. Type III collagen prevails among the interstitial collagens of the myocardial stroma of the ventricles in the heart of fetuses, one-day-old and seven-day-old newborns. Type I collagen is poorly represented in the myocardium of fetuses and one-day-old newborns observations, while in the seven-dayold newborns group its amount increases intensively. No significant difference was detected between type III collagen formation in the myocardium of fetuses and one-day-old newborns, while the amount of collagen type III significantly increased (Р≤0.05) in the seven-day-old newborns in the stroma of both ventricles of the heart. Collagen type IV is localized in the basal membranes of the myocardial microvessels of the heart ventricles of fetuses, one-day-old and seven-day-old newborns. No significant difference was found between the amount of this collagen type in the ventricles of fetuses and one-day-old newborns. A significant increase in collagen type IV in the basal membranes of capillaries and arterioles is noted in the ventricle myocardium of seven-day-old newborn rats (Р≤0.05). Conclusion. Thus, the results of the study point out the active formation of interstitial collagens types I and III, as well as collagen of basal membranes type IV in the ventricular myocardium of rats during the first seven days of postnatal development.