Effect of spinal cyclooxygenase inhibitors in rat using the formalin test and in vitro prostaglandin E2 release.
Spinally delivery of the non-specific cyclooxygenase inhibitor, S(+)-ibuprofen, reduces the second phase of the formalin test and the evoked release of prostaglandin E2 (prostaglandin E2) from rat spinal cord in vitro. Using two selective cyclooxygenase-2 inhibitors, SC58125 (1-[(4-methysufonyl)phenyl]-3-tri-fluoromethyl-5-(4-fluorophenyl)p yrazole) and SC-236 (4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzenesulfon amide), we observed that neither agent at the highest dose/concentration employed altered the second phase of the formalin test after intrathecal delivery or K+-evoked prostaglandin E2 release from spinal cord in vitro, although ibuprofen was effective in both models. These observations suggest that cyclooxygenase-2 may not be associated with spinal prostanoid synthesis acutely or with facilitated nociception which occurs within the limited time frame of the formalin test.
Dirig
D M
DM
Department of Pharmacology, University of California at San Diego, La Jolla 92093, USA.
Konin
G P
GP
Isakson
P C
PC
Yaksh
T L
TL
D000818:Animals; D016861:Cyclooxygenase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D015232:Dinoprostone / Q000378:metabolism*; D004558:Electric Stimulation; D005557:Formaldehyde; D066298:In Vitro Techniques; D007527:Isoenzymes / Q000378:metabolism; D008297:Male; D010147:Pain Measurement / Q000187:drug effects*; D010477:Perfusion; D011188:Potassium / Q000008:administration & dosage / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000187:drug effects* / Q000378:metabolism
D016861:Cyclooxygenase Inhibitors; D007527:Isoenzymes; D005557:Formaldehyde; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone; D011188:Potassium