A combination of palytoxin with 1-oleoyl-2-acetyl-glycerol (OAG) or insulin or interleukin-1 synergistically stimulates arachidonic acid metabolism, but combinations of 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-type tumor promoters with OAG do not

The combination of palytoxin and 1-oleoyl-2-acetyl-glycerol(OAG) synergistically stimulates production of 6-keto-PGF₁ andPGF₂ by rat liver cells (the C-9 cell line). In contrast, thecombination of 12-O-tetradecanoylphorbol-13-acetate (TPA)-typetumor promoters (TPA, dihydroteleocidin B, aplysiatoxin, phorbol-12,13-didecanoate)and OAG does not. Production of 6-keto-PGF₁ by palytoxin addedwith recombinant murine interleukin-1 (IL-1) or with insulinis also greater than the sum of the two effects taken independently.Palytoxin and OAG individually stimulate the release of radio-labeledcompounds from the rat liver cells pre-labeled with ³H]arachidonicacid and also act synergistically to release labeled metabolites.After separation by h.p.l.c., these materials co-chromatographwith authentic 6-keto-PGF₁ and arachidonic acid. The synergisticstimulation by palytoxin and OAG is biphasic; a rapid synergisticproduction of 6-keto-PGF₁ or release of radiolabel from ³H]arachidonicacid prelabeled cells is followed, after 2 –4 h, by aprolonged synergistic response.