Neonatal capsaicin pretreatment suppresses intramedullary inflammation in adjuvant-induced spondylitis.
In order to investigate the proposed involvement of neuropeptides in musculoskeletal inflammation we pretreated rats, in an adjuvant spondylitis model, with capsaicin, a neurotoxin. Immunohistochemistry showed that administration of capsaicin to newborn rats depleted irreversibly the neuropeptide, substance P. Elimination of capsaicin-sensitive fibres by the neonatal injection of capsaicin did not suppress the peridiscitis of rats in which adjuvant spondylitis was induced at 7 weeks of age. However, elimination of capsaicin-sensitive fibres did suppress the inflammation usually seen in the bone marrow. We speculate that this intramedullary inflammation is normally induced or sustained by capsaicin-sensitive fibres.
Imai
S
S
Department of Orthopaedic Surgery, Shiga University of Medical Science, Otsu-shi, Japan.
Hukuda
S
S
Maeda
T
T
D000818:Animals; D000831:Animals, Newborn; D002211:Capsaicin / Q000494:pharmacology*; D008297:Male; D009475:Neurons, Afferent / Q000502:physiology; D051381:Rats; D011917:Rats, Inbred Lew; D017208:Rats, Wistar; D013166:Spondylitis / Q000209:etiology* / Q000473:pathology / Q000517:prevention & control; D013373:Substance P / Q000502:physiology*
D013373:Substance P; D002211:Capsaicin