title: Changes in peptidergic fiber density in the synovium of mice with collagenase-induced acute arthritis.
abstract: The effect of acute osteoarthritis (OA) on peripheral nerve fibers (NFs) in synovial tissue, and their association with histological changes were investigated in collagenase-induced OA mice. Collagenase (10 U in 5 μL saline) was injected into the right knee, and the same volume of saline was injected into the left knee as the control. Mice were sacrificed 1, 2, 3, and 4 weeks after the collagenase injection. Histopathological changes in the knee joints were evaluated. The numbers of protein gene product (PGP) 9.5-, calcitonin-gene-related peptide (CGRP)-, and substance P (SP)-positive NFs in the synovial tissue were determined, and their densities in the tissue were calculated. The densities of PGP 9.5- and CGRP-positive NFs in the synovium were drastically decreased 1 week after the collagenase injection. However, by week 4, the density of PGP 9.5- and CGRP-positive NFs had recovered to 84% and 79% of their normal levels, respectively. Despite the poor correlation between the synovitis score and the density of CGRP- or SP-positive NFs in the synovium, the ossification rate of chondrophytes in chondro/osteophyte lesions correlated strongly with the density of CGRP-positive NFs (R = 0.855). These results suggest that the ossification of chondrophytes occurred in parallel with the increase in CGRP-positive fiber density in the synovium during the acute phase of collagenase-induced OA.
authors.affiliation: Laboratory of Toxicology, Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-ourai-kita, Izumisano-shi, Osaka 598-8531, Japan., Department of Veterinary Clinical Pathobiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Murakami
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakagawa
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nishimura
authors.forename: Saburo
authors.initials: S
authors.lastname: Matsuo
mesh_terms: D000818:Animals; D001168:Arthritis / Q000378:metabolism*; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D017364:Collagenases / Q000009:adverse effects* / Q000378:metabolism*; D007719:Knee Joint / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009412:Nerve Fibers / Q000378:metabolism*; D010003:Osteoarthritis / Q000378:metabolism; D013373:Substance P / Q000378:metabolism; D013583:Synovial Membrane / Q000378:metabolism*
chemical_list: D013373:Substance P; D017364:Collagenases; D015740:Calcitonin Gene-Related Peptide
keywords: arthrose; calcitonin gene-related peptide; fibres nerveuses périphériques; ossification; osteoarthritis; osteophyte; ostéophyte; peptide lié au gène de la calcitonine; peripheral nerve fibers; substance P; synovie; synovium