A phlogistic function of PGE1 in calcium pyrophosphate dihydrate crystal-induced inflammation.

Promotion of calcium pyrophosphate dihydrate (CaPPD) crystal-induced inflammation by prostaglandin (PG) E1 has been demonstrated by two new techniques: (1) Rats deficient in essential fatty acids, biological precursors of PG, developed less footpad swelling than did normal rats following injections of unheated CaPPD. Addition of one ng of PGE1 to these crystals resulted in normal swelling. (2) This phlogistic effect of PGE1 was also demonstrated in normal rats fed a normal dietwho received injections of CaPPD crystals heated to 200 degrees C for three hours. The heated crystals induced less footpad swelling than did unheated crystals. When one ng of PGE1 was added to the suspensions of heated crystals the resultant swelling approximated that obtained by unheated crystals. The possible role of PGE1 in mediating CaPPD crystal-induced inflammation is suggested. An analysis of urate and CaPPD crytal-induced inflammation is presented with comments setting forth the concept that these metabolic crystal disorders are membrane diseases.