Relationship between Neuropeptide lmmuno reactive Nerves and Inflammatory Cells in Adjuvant Arthritic Rats

Abstract

Konttinen YT, Hukkanen M, Segerberg M, Rees R, Kemppinen P, Sorsa T, Saari H, Polak JM, Santavirta S. Relationship between Neuropeptide Immunoractive Nerves and Inflammatory Cells in Adjuvant Arthritic Rats. Scand J Rheumatol 1992; 21: 55–9.

The purpose of this study was to assess the relationship of neuropeptide nerves and inflammatory leukocytes in PVG rats with adjuvant-induced arthritis. Substance P- and calcitonin gene-related peptide (CGRP)-immuno reactive nerves and inflammatory leukocytes were studied, using peroxidase (ABC) andor alkaline phosphatase (APAAP) staining. Inflamed synovial tissue proper was infiltrated with neutrophils, ED1 macrophages and focal accumulations of CD2 T lymphocytes. In such tissue, the relationship between peptide-immuno reactive nerves and inflammatory cells was such that substance P and CGRP nerves were absent in heavily infiltrated villous synovial tissue, whereas healthy synovial tissue and non-inflammatory areas in adjuvant arthritic rats were innervated by substance P and CGRP nerves close to normal synovial tissue resident cells. In order to elucidate an eventual mechanism for lost immuno reactivity, healthy synovial tissue was exposed to chymotrypsin or oxygen derived free radicals (ODFR) in vitro. The former treatment caused total loss of immuno reactivity. These findings suggest that neuropeptides and neuropeptide containing nerves may be destroyed by locally produced proteolytic enzymes and various reactive oxygen species in the vicinity of inflammatory cells.

Key Words:

• neurotransmitters
• neurogenic inflammation
• arthritis