The distribution of cyclooxygenase-1 in human temporomandibular joint samples: an immunohistochemical study.

Cyclooxygenase-1,2 (COX-1,2) or prostaglandin (PG) H synthase, is the first enzyme of the pathway in which arachidonic acid is oxidized to PGs. Thus, we examined the expression of COX-1 in 16 human temporomandibular joint (TMJ) samples with internal derangement and in 10 control specimens by an immunohistological technique using paraffin-embedded tissue and specific antihuman COX-1 polyclonal antibody. There was obvious distinction of COX-1 immunoreactivity between the control specimens and internal derangement cases, at the endothelial cells and fibroblasts, in the region of posterior and/or anterior loose connective tissues and synovial membrane. The findings of the present study suggest that COX-1 might be an important mechanism for maintaining normal homeostasis at the endothelial cells and fibroblasts with internal derangement of TMJ.