Release of histamine and formation of prostaglandins in human lung tissue and rat mast cells.

Release of histamine and prostaglandins (PGs) from human lung tissue and rat mast cells was investigated. Passively sensitized lung fragments released PGE, PGF2alpha and the 15-ketodihydro metabolites into the media with time alone. Antigen challenge liberated 20% tissue histamine and there was a twofold increase in PGs. Twice as much PGF2alpha as PGE was found. beta-Adrenergic agonists inhibited the anaphylactic release of mediators and this action was blocked by propranolol. Both PGF2alpha and PGE were consistently found in the mast cell media, demonstrating that mast cells can synthesize PGs. Anaphylaxis induced a marked liberation of histamine but not of PGs. The results indicate that the release of histamine may precede the major release of PGs and suggest that the bulk of PGs may derive from cells in the proximity of the mast cells.