Prolonged opportunity for neuroprotection in experimental stroke with selective blockade of cyclooxygenase-2 activity.
The post-treatment effects of the selective cyclooxygenase (COX)-2 inhibitor, valdecoxib, were investigated in a rat model of temporary focal ischemia. Valdecoxib reduced basal brain prostaglandin E(2) concentrations at dosages that did not affect serum thromboxane B(2), consistent with a selective COX-2 effect. Temporary focal cerebral ischemia was produced in rats by middle cerebral artery occlusion for 90 min. There was increased expression of COX-2 protein detected by Western blot and immunocytochemistry within neurons in the ischemic cortex at 4 and 24 h after ischemia. Rats were treated with vehicle or valdecoxib 15 min before or 1.5, 3 and 6 h after cerebral ischemia. Rats were sacrificed and brain infarction volume determined 24 h after ischemia. Valdecoxib treatment was associated with a decrease in infarction volume when administered 15 min before, and 1.5 or 3 h but not 6 h after cerebral ischemia. There were no differences in physiological parameters during the procedure. Valdecoxib administered at 1.5 h after ischemia significantly reduced the concentrations of prostaglandin E(2) in ischemic penumbral cortex as compared to the vehicle-treated group and contralateral non-ischemic cortex. These results suggest that COX-2 inhibition with valdecoxib is effective when initiated both before and after middle cerebral artery occlusion.
Ahmad
Muzamil
M
Geriatric Research Educational and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh, PA 15205, USA.
Zhang
Yuquin
Y
Liu
Hao
H
Rose
Marie E
ME
Graham
Steven H
SH
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D002560:Cerebrovascular Circulation / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000378:metabolism; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology*; D015232:Dinoprostone / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D020244:Infarction, Middle Cerebral Artery / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D007555:Isoxazoles / Q000494:pharmacology*; D008297:Male; D009474:Neurons / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013449:Sulfonamides / Q000494:pharmacology*; D013929:Thromboxane B2 / Q000097:blood; D013997:Time Factors; D000096926:Benzenesulfonamides
D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D015232:Dinoprostone; D007555:Isoxazoles; D018696:Neuroprotective Agents; D013449:Sulfonamides; D013929:Thromboxane B2; C406224:valdecoxib; D000096926:Benzenesulfonamides