Without the mast cell protease Mc-cpa, most mice die within an hour of being injected with ET-1.
High blood pressure and septic shock are both enhanced by a 21–amino acid peptide called ET-1. This peptide is secreted by blood vessel cells that have been activated by inflammatory cytokines. ET-1 triggers the contraction of smooth muscle cells that are wrapped around blood vessels, causing blood to flow through the squeezed vessels at a higher pressure. This contraction prevents blood from getting to its target tissues, leading to sepsis-associated organ malfunction.
ET-1 is structurally similar to a snake venom toxin called sarafotoxin. This toxin is lethal to mice that lack a type of immune cell called mast cells. These mice also die when sepsis-causing...
