INCREASED LEVELS OF SUBSTANCE-P AND CALCITONIN-GENE-RELATED PEPTIDE IN RAT ADJUVANT ARTHRITIS - A COMBINED IMMUNOHISTOCHEMICAL AND RADIOIMMUNOASSAY ANALYSIS

Objective. To analyze the occurrence of substance P (SP) and calcitoni n gene-related peptide (CGRP) in ankle joints and corresponding dorsal root ganglia (L2-L6) of rats with adjuvant arthritis. Methods. Arthri tis was induced by inoculation with heat-killed mycobacteria. The morp hologic distribution of SP and CGRP was assessed by immunohistochemica l analysis. Tissue concentrations of the neuropeptides were determined by radioimmunoassay. Results. Neuronal CGRP-like immunoreactivity was clearly increased in the synovium and the dorsal root ganglia, wherea s the increase in SP-positive structures was less pronounced, The tiss ue concentrations of SP and CGRP were significantly increased both in ankle joints and in dorsal root ganglia. Conclusion. Levels of sensory neuropeptides are increased under conditions of joint inflammation.