Morphological changes of rat atrial cardiomyocytes contractile apparatus in normal conditions and under the influence of acute and chronic prenatal hypoxia. Role of α-smooth muscle actin in myofibrilogenesis.

Autor: K. M. Shevchenko
Jazyk: Russian<br />Ukrainian
Rok vydání: 2016
Předmět:
Zdroj: Морфологія, Vol 10, Iss 2, Pp 85-92 (2016)
Druh dokumentu: article
ISSN: 1997-9665
DOI: 10.26641/1997-9665.2016.2.85-92
Popis: Background. There are only a few researches considering the influence of hypoxia on myofibrils formation and cardiomyocytes differentiation. However the role of α-smooth muscle actin on sarcomyogenesis is still unclear, that leads to the further study of this question. Objective. The purpose of the work was to determine ontogenetic changes of myofibrils and cardiomyocytes differentiation in rat atrial myocardium in normal conditions and under the influence of acute and chronic prenatal hypoxia. Methods. Embryo hearts were investigated on 14th, 16th days of prenatal ontogenesis, newborn rat hearts and the hearts of rats – on 30th day of postnatal ontogenesis. Animals were subdivided into three groups: 1stexperimental group of animals was exposed to acute prenatal hypoxia, 2nd experimental group animals was exposed to chronic prenatal hypoxia and control group animals. Hypoxia modeling was conducted on pregnant females by injection of 1% sodium nitrite intraperitonealy in doses that lead to moderate hypoxia. During the work complex of histological, immunohistochemical and electron microscopy methods were used. Antibodies to α-smooth muscle actin (α-SMA) were used to study cardiomyocytes differentiation. The digital images were analyzed using a computer with NIH ImageJ program. Results and conclusion. The results show that myofibrillar differentiation is associated with reduction of α-SMA expression. Ultrastructural changes of rat atrial cardiomyocytes in 3 days after the influence of acute prenatal hypoxia manifested in disruption of myofibrillar orientation, accompanied with decreasing α-SMA expression. Chronic prenatal hypoxia from 16thday of prenatal ontogenesis to the 1stday of postnatal ontogenesis manifestated in myofibrillar defragmentation and disorientation, associated with decreased α-SMA expression compared with the control group. Conclusion. α-SMA can be used as a marker of cardiomyocytes differentiation.
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