Periarthritis promotes gait disturbance in zymosan-induced arthritis in rats.
OBJECTIVE
We studied the contribution of periarthritis and synovitis to gait disturbance in zymosan (Zy)-induced arthritis.


METHODS
Sixty Wistar rats were subjected to injection of Zy (1 mg) into their right knee joints. A first group of animals (GI) had Zy injected through the intact skin. A second group (GII) had Zy injected directly into the articular cavity after excision of the skin and subcutaneous tissue surrounding the joint. Gait disturbance was evaluated using the rat-knee joint incapacitation test. Increase in vascular permeability and cell influx were assessed in joint fluids and joint histology was performed.


RESULTS
Zy injection induced a dose-dependent gait disturbance which was maximal at the third/fourth hour of arthritis, being significantly greater in GI rats, whereas cell influx (neutrophils > or = 80%) was maximal at the sixth hour. Cell influx and increase in vasopermeability did not differ between both groups. Histology revealed no significant difference between GI and GII. A third group (GIII), subjected to immune-complex arthritis, that received anti-bovine serum albumin (BSA) antibodies intra-articularly and BSA i.v., did not present gait disturbance, despite the increase in cell counts.


CONCLUSIONS
Vascular permeability increase and cell influx are phenomena independent of gait disturbance. Neutrophils do not seem to contribute to development of gait disturbance in Zy arthritis. Sensitization of specific pain receptors in periarticular rather than in synovial tissue is responsible for gait disturbance in Zy-induced arthritis.
Rocha
F A
FA
Faculdade de Medicina, Departamento de Fisiologia e Farmacologia e Departamento de Medicina Clinica, Universidade Federal do Ceará, Fortaleza CE, Brazil. arocha@ufc.br
Aragão
A G
AG
Oliveira
R C
RC
Pompeu
M M
MM
Vale
M R
MR
Ribeiro
R A
RA
D000818:Animals; D000906:Antibodies / Q000008:administration & dosage; D000936:Antigen-Antibody Complex; D001168:Arthritis / Q000276:immunology / Q000503:physiopathology; D002199:Capillary Permeability; D005684:Gait; D007700:Kinetics; D007719:Knee Joint / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology; D008297:Male; D010489:Periarthritis / Q000139:chemically induced* / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D012710:Serum Albumin, Bovine / Q000276:immunology; D015054:Zymosan / Q000008:administration & dosage
D000906:Antibodies; D000936:Antigen-Antibody Complex; D012710:Serum Albumin, Bovine; D015054:Zymosan