Locomotion and muscle mass measures in a murine model of collagen-induced arthritis.
BACKGROUND
Rheumatoid arthritis (RA) is characterized by chronic poly-arthritis, synovial hyperplasia, erosive synovitis, progressive cartilage and bone destruction accompanied by a loss of body cell mass. This loss of cell mass, known as rheumatoid cachexia, predominates in the skeletal muscle and can in part be explained by a decreased physical activity. The murine collagen induced arthritis (CIA) model has been proven to be a useful model in RA research since it shares many immunological and pathological features with human RA. The present study explored the interactions between arthritis development, locomotion and muscle mass in the CIA model.


METHODS
CIA was induced in male DBA/1 mice. Locomotion was registered at different time points by a camera and evaluated by a computerized tracing system. Arthritis severity was detected by the traditionally used semi-quantitative clinical scores. The muscle mass of the hind-legs was detected at the end of the study by weighing. A methotrexate (MTX) intervention group was included to study the applicability of the locomotion and muscle mass for testing effectiveness of interventions in more detail.


RESULTS
There is a strong correlation between clinical arthritis and locomotion. The correlations between muscle mass and locomotion or clinical arthritis were less pronounced. MTX intervention resulted in an improvement of disease severity accompanied by an increase in locomotion and muscle mass.


CONCLUSIONS
The present data demonstrate that registration of locomotion followed by a computerized evaluation of the movements is a simple non invasive quantitative method to define disease severity and evaluate effectiveness of therapeutic agents in the CIA model.
Hartog
Anita
A
Danone Research, Centre for Specialised Nutrition, Wageningen, The Netherlands. Anita.Hartog@danone.com
Hulsman
Judith
J
Garssen
Johan
J
D000818:Animals; D018501:Antirheumatic Agents / Q000494:pharmacology / Q000627:therapeutic use; D001169:Arthritis, Experimental / Q000150:complications* / Q000188:drug therapy / Q000503:physiopathology; D001835:Body Weight / Q000502:physiology; D002100:Cachexia / Q000188:drug therapy / Q000209:etiology* / Q000503:physiopathology; D004185:Disability Evaluation; D004195:Disease Models, Animal; D018450:Disease Progression; D020233:Gait Disorders, Neurologic / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology*; D007091:Image Processing, Computer-Assisted; D008124:Locomotion / Q000187:drug effects / Q000502:physiology; D008297:Male; D008727:Methotrexate / Q000494:pharmacology / Q000627:therapeutic use; D051379:Mice; D008811:Mice, Inbred DBA; D018482:Muscle, Skeletal / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D009133:Muscular Atrophy / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology*; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014741:Video Recording
D018501:Antirheumatic Agents; D008727:Methotrexate