Influence of experimental SAH on effects of COX-1 .COX-2 and 5-LOX inhibitors in nicotine-induced endotheliumdependent contraction(EDC) in rat basilar artery

The experiments were undertaken to examine influence of experimental SAH on effects of COX-1 , COX-2 and 5-LOX in nicotine-induced EDC in rat basilar artery. The basilar artery at 1 hour (early phase) and 7 days (late phase) after blood injection (SAH) was cut into a spiral preparation. Nicotine (3x10-3M) caused an EDC in rat basilar artery. The presence of COX-1 inhibitor (flurbiprofen and ketoprofen at 01-5 to 10-4 M) and 5-LOX inhibitor (zm230487 at 10-8 to 10-6 M) in normal and SAH (early and late phases) attenuated the EDC in a concentration-dependent manner and the inhibitory effect of COX-2 (L-745337 at 10-5 to 10-4 M and nimesulide at 10-7 to 10-4 M) in SAH (late phase) was significantly less than those of normal and SAH (early phase) was significantly less than those of normal and SAH (early phase). From these results, it was suggested that the experimental SAH at the late phase modified COX-2 activities in nicotine-induced EDC in rat basilar artery and COX-l and 5-LOX haven't been affected by SAH (early phase and late phase).