Mast cells and endothelin-1: a life-saving biological liaison?

Over a decade ago endothelin-1 (ET-1) was described as belonging to the assortment of mast cell-derived and mast cell-bound cytokines. Mast cell subtype- and environment-dependent, ET-1 acts as a potent non-immunological mast-cell activator, which leads to degranulation and mediator release. The biological significance of this phenomenon remained obscure; however, a recent report sheds new light on this delicate mast cell–ET-1 connection. The authors of this report use mast cell-deficient mice to provide convincing evidence that mast cells counteract the toxicity induced by high concentrations of ET-1, and thereby promote homeostasis.