Stimulation of arachidonic acid metabolism by human slow-reacting substances.

Human slow-reacting substance of anaphylaxis (SRS-A) and calcium ionophore-induced human SRS released prostaglandin-like substances and rabbit aorta contracting substance (RCS) from guinea-pig lungs. This effect was abolished by incubation of SRS-A and SRS with arylsulphatase or pretreatment of the lungs with indomethacin. Human SRS-A and SRS therefore resembled guinea-pig SRS-A in stimulating arachidonic acid metabolism. These results provide further evidence for a similar (or identical) nature of human SRS-A and SRS and suggest a possible role for slow-reacting substances in the release of prostaglandins during anaphylaxis.