Immunohistochemical Study of Heart Morphogenesis Disorders in Rats in Terms of Lead Acetate Exposure at the Prenatal Stage of their Development

There are several publications dedicated to the heart morphogenesis, the articles describing the influence of various cytotoxic compounds on embryonic development are also of considerable interest. Negative effects of intoxication with lead compounds on the development of the cardiovascular system are well-known. In addition to acute toxic effects, lead accumulates in the heart and, causing pathobiochemical processes, provokes a developmental disorder. The emergence of new and modern methods of research in experimental embryology, such as electronic microscopy and immunohistochemistry, allows us to obtain new data on the cytological and morphofunctional patterns of cardiac morphogenesis. The purpose of the study was to analyze the issues of rat morphogenesis disorders under the influence of lead acetate on prenatal development and under conditions of correction of lycopene and inulin. Material and methods. Experiments were performed on Wistar rats, females (average weight 200-220 g). Animals kept the vivarium in the standard conditions: air temperature 22 ± 2° С, humidity 55 ± 15%, 12-hour light / dark cycle, free access to water and food. Intact pregnant females were given distilled water (group 1). Group 2 pregnant females were administered 2.5 g% solution of lead acetate intragastrically at a rate of 50 mg / kg of body weight per day (via a probe once daily for the entire duration of pregnancy). A separate group consisted of animals administered lead acetate and lycopene (group 3) and inulin (group 4). Aqueous solutions of lycopene (Hubei Pharmaceutical) and inulin were injected in a similar manner at a rate of 500 mg / kg of body weight per day. Results and discussion. The results of the studies showed new data on cardiac morphogenesis disorders on prenatal development with intoxication with lead compounds, a new approach to the study of normal and pathological development of the heart. The results of morphometric studies indicated a reduction in the area of nuclei of cardiomyocytes in groups administered lead acetate. Lead acetate suppresses cardiac morphogenesis in the prenatal period, which at the morphological level delays development and damage to the right and left atrium myocardium and right ventricle. The general manifestation of disturbed cardiac morphogenesis on E14-E18 was the reduction in cardiac myocardial density in the myocardium, decreasing the size of the nuclei of cardiomyocytes, increasing the interstitial space in the cortical (outer) layer and the intervals in the trabecular (internal) layer of the myocardium, decreasing the density and blood filling. Structural changes in embryos of stage E16 were delayed myocardial development, which affected the lower density of cardiomyocytes in the ventricles and atriums, the appearance of focal cells of the empty interstitial space, which may be evidence of edema. For all markers used (α-SMA, MMP-9 and VEGF), there was a finding of cardiac morphogenesis, structural and metabolic changes. Conclusion. The immunohistochemical study revealed suppression of expression of α-SMA, MMP-9 and VEGF in the myocardium within terms of 14, 16, 18 days of prenatal development, which is the manifestation of structural and functional damage to cardiomyocytes. The use of lycopene and inulin during the pregnancy of rats contributed to the restoration of the left atrium and right ventricle.