Beschreibung:
<jats:p><jats:bold>Introduction</jats:bold>. Melatonin, being a powerful endogenous antioxidant, provides healthy course of pregnancy and childbirth. Decrease of melatonin levels in blood correlates with severity of preeclampsia. Currently, melatonin is viewed as a perspective antioxidant, able to improve mother’s condition during preeclampsia and protect fetus from unfavorable intrauterine environment.</jats:p><jats:p><jats:bold>The objective </jats:bold>was to study melatonin effects on remodeling of chicken embryo heart tissue under normal conditions and under oxidative stress model.</jats:p><jats:p><jats:bold>Materials and methods</jats:bold>. The study was performed using organotypic culture of heart tissue of 10–12-day-old chicken embryos. Oxidative stress was modeled by adding epinephrine 10<jats:sup>–4</jats:sup> М or homocysteine thiolactone 10<jats:sup>–3</jats:sup> М to culture medium.</jats:p><jats:p><jats:bold>Results</jats:bold>. The trophotropic effects of melatonin was detected at a concentration of 10–6 M. Drug stimulated heart tissue explants’ growth on 20 %. Epinephrine showed cardiotoxic effects at concentrations of 10<jats:sup>–4</jats:sup> and 10<jats:sup>–6</jats:sup> М. Melatonin (10<jats:sup>–6</jats:sup> М) neutralized cardiotoxic effects of epinephrine (10<jats:sup>–4</jats:sup> M). Cardiotoxic effects of homocysteine thiolactone (10<jats:sup>–3</jats:sup> М) preserved in presence of melatonin (10<jats:sup>–6</jats:sup> М).</jats:p><jats:p><jats:bold>Conclusion</jats:bold>. During embryonic period, melatonin neutralizes cardiotoxic effects of oxidative stress caused by a high concentration of epinephrine, but not by homocysteine thiolactone. </jats:p>