Inhibition of 5-LO product formation by MK886 abolishes the sex differences in PG formation in the thoracic exudates of carrageenan-treated rats. Rats were pre-treated with MK886 (1.5 mg/kg, i.p.) or vehicle (DMSO 2%, i.p.) 30 min prior to carrageenan intrathoracic injection and sacrificed after 4 hrs. (A) PGE2, (B) 6-keto-PGF1α, and (C) LTB4 levels in the exudates. (D) Number of infiltrated cells. Values represent means ± S.E.M; n = 6 rats; #p < 0.05, male vs female; °p < 0.05, female control rats vs female rats treated with MK886; two-tailed Student’s t test.