INCREASED LEVELS OF CYCLOOXYGENASE-2 MESSENGER-RNA IN THE RAT SPINAL-CORD AFTER PERIPHERAL INFLAMMATION - AN IN-SITU HYBRIDIZATION STUDY

CYCLOOXYGENASE-2 (COX-2) is considered to play a major role in inflamm ation processes by catalyzing the production of prostaglandins (PGs). Using in situ hybridization histochemistry we studied the localization of COS-1 and COX-2 mRNA in the spinal cord and dorsal root ganglia (D RGs) after peripheral inflammation or after axotomy in the rat. No COX -2 mRNA signals were detected in the spinal cord under normal conditio ns, but strong expression was seen bilaterally in non-neuronal cells w ithin the grey and white matter and along the leptomeninges and blood vessels 6 h after unilateral carrageenan injection into the hind paw, but not after peripheral nerve injury. The results suggest that COX-2 expressed in non-neuronal cells contributes to PG production in and ar ound the spinal cord under peripheral inflammatory processes.