The Effect of Thiols on the Immunologic Release of Slow Reacting Substance of Anaphylaxis

Abstract

In the presence of L-cysteine, a selective and marked enhancement of the in vitro, immunologic release of slow reacting substance of anaphylaxis (SRS-A) from human peripheral leukocytes, sensitized monkey lung fragments, and sensitized guinea pig lung fragments was observed. In the rat, cysteine, but not sodium sulfide, enhanced the calcium ionophore (A23187)-induced release of SRS-A in vitro from mixed rat peritoneal cells and in vivo from the rat peritoneal cavity. Pretreatment of rats with cysteine also enhanced the IgGa- and anti-rat IgE-mediated release of SRS-A in vivo in the rat. These studies indicate a common biochemical mechanism involved in the formation and release of SRS-A from these different tissues and cells and further confirm the observation that the rat mast cell is not a major source of SRS-A in the rat.