Identification of Mast Cells and Immunophenotypic Subtypes in Peripheral Nerve Damage Caused by Epineurotomy and Systemic Inflammation

Abstract

ABSTRACT Purpose: This study aims to investigate the numerical increase, localization, granulation status, and immunophenotypic properties of mast cells (MCs) in epineurectomy-induced nerve damage and lipopolysaccharide (LPS)-induced systemic infection models. Materials and Methods: In this study, the animals were divided into three groups of 6 each. One of the groups was determined as the control group, epineurectomy was applied to one group, and systemic inflammation was created by regular LPS injections in the other group. Then, the obtained nerve tissues were stained histochemically with Hematoxylin and Eosin toluidine blue, and the increase, localization, and granulation status of MCs were examined. Immunohistochemically, antitryptase and antichymase staining were performed to determine the immunophenotypes of MCs. Results: As a result, while the number of MCs increased in both groups compared to the control group, MCs in the LPS group were in the epineurium, and MCs in the epineurotomy group were located between the nerve fibers. While MCs in the LPS group showed very severe degranulation, mild degranulation was observed in the epineurotomy group, and almost no degranulated MCs were observed in the control group. Conclusion: This study is critical because it is one of the first studies to compare MCs in different nerve damage types and examine the expression of chymase and tryptase.