Neuroendocrine cells in Malassez epithelium and gingiva of the cat

Area of Science:

• Veterinary Anatomy
• Histology
• Neuroendocrinology

Background:

• Malassez epithelium, also known as epithelial cell rests, has an unclear biological significance.
• The presence of neuroendocrine cells within Malassez epithelium has not been previously established.

Purpose of the Study:

• To investigate the presence and localization of neuroendocrine cells within Malassez epithelium in mature cats.
• To examine Malassez epithelium for specific neuropeptides: calcitonin gene-related peptide (CGRP), substance P (SP), and vasoactive intestinal peptide (VIP).

Main Methods:

• Immunohistochemistry, confocal microscopy, and light microscopy were employed.
• Malassez epithelium and gingival epithelium (positive control) from five mature cats were analyzed.
• Cells were examined for immunoreactivity to CGRP, SP, and VIP, with double immunolabeling used to assess co-expression.

Main Results:

• Cells immunoreactive to CGRP, SP, and VIP were consistently found in Malassez epithelium and gingival rete pegs.
• Immunopositive cells were predominantly located in the cervical half of the periodontal ligament within Malassez structures.
• Co-expression of CGRP or SP with VIP was observed, with neuropeptides localized within cellular compartments. Occasional association with nerve fibers was noted.

Conclusions:

• The study confirms the presence of neuroendocrine cells expressing CGRP, SP, and VIP in cat Malassez epithelium.
• This finding demonstrates the cellular diversity of Malassez epithelium, similar to other epithelial tissues.
• The identified neuropeptides suggest potential endocrine functions for Malassez epithelium, contributing to its biological significance.