“…26 This new and very interesting concept was explained in detail by Uvnas, Patkar and Diamant who described the mechanisms of histamine release from rat peritoneal mast cells (see Kazimierczak and Diamant"). It was extended by Pearce who reported on the considerable functional heterogeneity of mast cells from different species and within the same species from different t i s s~e s .~~-~~ Thus the concept of 'atypical' mast cells, mast cell plasma membranes and mast cell granules as a mechanism for adverse reactions to drugs, especially in the case of anaesthetic agents being dissolved in Cremophor El put the mechanism of these reactions back to the target celL4 This concept, of course, is complementary, not contradictory to the immunological and nonimmunological humoral mechanisms which have been studied in so much detail.Ig…”