A finding of lasting pharmacological interest from these studies was the identification and partial isolation of the slow-reacting substance of anaphylaxis.

The cysteinyl leukotrienes make up the slow-reacting substance of anaphylaxis (SRS-A).

The Slow-reacting substance of anaphylaxis or SRS-A is a mixture of the leukotrienes LTC4, LTD4 and LTE4.

The slow reacting substance of anaphylaxis comprises the cysteinyl leukotrienes.

The investigations encompassed not only histamine, but also lysocithin (now lysolethicin) and identified a new agent, the slow reacting substance of anaphylaxis (SRS-A), plus a related SRS that was released in response to direct tissue insult.