Stimulated release of arachidonic acid by agonists of the peroxisome proliferator-activated receptor and retinoic acid receptors

Release of arachidonic acid from rat liver cells is stimulated after a 6-hour incubation with 9-cis retinoic acid, all trans retinoic acid, the selective peroxisome proliferator-activated receptor-gamma synthetic thiazolidinedione, ciglitazone, the cyclopentenones,15-deoxy-Delta (12,14) PGJ(2) and PGJ(2) and the non-steroidal anti-inflammatory drugs, celecoxib and indomethacin. The rates of the release stimulated by 15-deoxy-Delta (12,14) PGJ(2) differ from those observed with celecoxib. Arachidonic acid release by 9-cis retinoic acid in the presence of either ciglitazone or trans retinoic acid is synergistic. It is additive in the presence of celecoxib. Cycloheximide and actinomycin inhibit the release of arachidonic acid stimulated by 15-deoxy-Delta (12,14) PGJ2 but not by celecoxib. The findings indicate that agonists of the peroxisome proliferator-activated receptor-gamma and retinoic acid receptors stimulate the release of arachidonic acid. The mechanisms involved may differ in the cases of 15-deoxy-Delta (12,14) PGJ(2) and celecoxib. (C) 2001 Harcourt Publishers Ltd.