Interaction between prostaglandins E and F given intradermally in the rat

1. Increases in permeability observed after intradermal injection of prostaglandins PGE(1) or PGE(2) (0.1 mug) into rats were greatly reduced when they were given in admixture with PGF(2alpha). This effect was not seen with PGF(1alpha) at doses of 0.5-1 mug.2. Effects of the histamine releasing agent compound 48/80 (25 ng) were inhibited by PGF(2alpha) (0.5 mug) but not by PGF(1alpha) (0.5 mug).3. Responses to histamine (1 mug), 5-hydroxytryptamine (0.1 mug) and bradykinin (1 mug), which have a direct action on the microvasculature, were not significantly altered by PGF(2alpha) (0.5 mug).4. It is concluded that PGF(2alpha) probably acts by interfering with the release of mast cell histamine by PGE(1), PGE(2) and compound 48/80.