S100ß are immunopositive glial cells of the rat heart in early postnatal ontogenesis

The study of the innervation of the main organ of the cardiovascular system, the heart, is an important problem of modern neurobiology. Most research on this topic is devoted to the study of nervous structures in humans and animals; glial cells are studied less. Nevertheless, glia plays an important role in maintaining the metabolism of the nervous apparatus and, by producing biologically active substances, affects the state of tissues and organs, both normally and in pathology. The purpose of this work is to study glial cells in the rat heart in the early postnatal period of development using an immunohistochemical marker, the S100β protein. The object of the study was the heart of Wistar rats at the age of seven days of postnatal development (P7) (n=12). Using immunohistochemical detection of a neural marker - the PGP 9.5 protein, the neural structures of the heart of P7 rats were studied. To identify glial cells, immunohistochemical detection of the S100β protein was used. The S100β protein belongs to the group of calcium-binding proteins and is expressed in glial cells of the central and peripheral nervous system. The study revealed a significant difference in the innervation of the upper and middle parts of the heart of P7 rats. Only in the right atrium was a pronounced concentration of nerve structures found, mainly in the region of the sinus node. It was established that in P7 rats, proepicardial cells express the S100β protein, characteristic of neurolemmocytes. A hypothesis has been put forward about the pos sibility of developing part of the glial cells of the myocardium of the right atrium and right ventricle from progenitor multipotent cells of the proepicardium through epithelialmesenchymal transformation.