Effects of prostanoid receptor agonists on immunologically-activated rat peritoneal mast cells.

Both the activation of tissue mast cells and the local generation of prostanoids are often associated with the pathogenesis of inflammatory conditions. Apart from the relationship that the mast cell is a source of prostanoids, it has also been demonstrated that exogenous prostaglandins (PG), in particular PGD2 and PGE2, can inhibit histamine release from rat mast cells at micromolar concentrations by increasing the intracellular cAMP levels [1, 2]. Although prostanoid receptors are now pharmacologically divided into DP, EP, FP, IP and TP receptors in terms of their selectivity for PGD2, PGE2, PGF2a, prostacyclin and TXA2 respectively [3], data concerning the characteristics of prostanoid receptors on mast cells are still limited. By comparing the actions of different selective prostanoid agonists on purified rat peritoneal mast cells, we attempted to systematically clarify this issue and the preliminary results in our study are discussed in this paper.