| Abstract: | Guinea-pig skin fragments were passively sensitized for the antigen-induced release of histamine, SRS-A and ECF-A. Skin histamine was chemically identified by fluorimetry; SRS-A gave a characteristic dose-dependent contraction of the guinea-pig ileum; and ECF-A selectively attracted eosinophils. The antibody mediating the release of these agents was shown to be IgG1. Following antigen challenge different time courses of release were demonstrable for histamine, SRS-A and ECF-A. Skin SRS-A was resistant to treatment with the enzyme pronase and skin ECF-A had an estimated molecular size of between 500 and 1000. They were therefore comparable to similar agents released from the lung. Thus SRS-A and ECF-A join histamine as chemical mediators in cutaneous anaphylaxis. |
