Immunohistochemical features of the human carotid body

Introduction. The carotid body is a chemoreceptor organ and the initial link of the reflex regulation of car-diovascular and respiratory systems. However, molecular genetic and immunohistochemical characteristics of the human carotid body remains underinvestigated. Although there are numerous studies of the second half of the 20th century devoted to the classical light-optical histology of the human organ, the immunohis-tochemical investigations are very few. The aim of our study was to clarify immunohistochemical features of the human carotid body in comparison with those of the most commonly used laboratory animals. Materials and methods. The study was performed on 10 carotid bodies of the adult human of different ages of both sexes using immunoperoxidase labeling with antibodies to bIII-tubulin, tyrosine hydroxylase, syn-aptophysin, PGP9.5, neurofilaments 200kDa, S100, and GFAP. Results. Nerve fibers passing between the lobules, as well as entering them, were positive for bIII-tubulin, tyrosine hydroxylase, PGP9.5 and neurofilaments. Type I cells had cytoplasmic reaction for bIII-tubulin and synaptophysin as well as cytoplasmic and nuclear staining for PGP9.5. At the same time, they had weaker reaction for tyrosine hydroxylase. Type II cells were positive for GFAP and S100. Conclusion. Immunohistochemical characteristics of the human carotid body were similar to those of rats and mice. The human carotid body cells and nerve fibers showed the same distribution of PGP9.5, bIII-tubulin, synaptophysin, neurofilaments, GFAP and S100 as rat and mouse carotid body cells. However, human carotid body reaction for tyrosine hydroxylase was much lower, which may indicate a smaller amount of synthesized catecholamines compared to the carotid body in rats and mice. Keywords: human carotid body, immunohistochemistry, sympathoadrenal system, tyrosine hydroxylase