Neuropeptidergic innervation of equine synovial joints.
Immunocytochemical analysis of equine synovial membranes revealed presence of several neuropeptides, including substance P (SP), neurokinin A, and neuropeptide Y, in nerves of the radiocarpal, middle carpal, and metacarpophalangeal (fetlock) joints. Within the subsynovium, these neuropeptides were located perivascularly, whereas in the fronds, only neuropeptide Y was restricted to the vessels of the synovial membrane. Only SP and neurokinin A were found in the intimal layer. The intimal layer of the metacarpophalangeal joint contained more SP-immunoreactive fibers than were observed in the intimal layer of the radiocarpal joint. Substance P also was detected in the synovial fluid from all 3 joints, but mean +/- SD concentrations were significantly different only between the middle carpal joint (37.56 +/- 5.48 fmol/ml; n = 6) and the metacarpophalangeal joint (55.80 +/- 8.33 fmol/ml; n = 5) and between the middle carpal joint and the radiocarpal joint (52.43 +/- 14.60 fmol/ml; n = 7).
Bowker
R M
RM
Department of Anatomy, Michigan State University, East Lansing 48824.
Abhold
R H
RH
Caron
J P
JP
Sonea
I M
IM
Vex
K B
KB
Kotyk
R
R
D000818:Animals; D005260:Female; D005552:Forelimb; D006736:Horses / Q000033:anatomy & histology* / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D015288:Neurokinin A / Q000378:metabolism; D009478:Neuropeptide Y / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism*; D013373:Substance P / Q000378:metabolism; D013583:Synovial Membrane / Q000294:innervation* / Q000378:metabolism*
D009478:Neuropeptide Y; D009479:Neuropeptides; D013373:Substance P; D015288:Neurokinin A