Endothelin/sarafotoxin family

General Vertebrate endothelins (ETs) are the most potent vasoconstrictors known. They stimulate cardiac contraction, regulate release of vasoactive substances and stimulate mitogenesis in blood vessels in primary culture. They also stimulate contraction in almost all other smooth muscles (e.g., uterus, bronchus, vas deferens and stomach) and stimulate secretion in several tissues (e.g., kidney, liver and adrenals).

Snake venom sarafotoxins (SRTXs) are structurally and functionally similar to endothelins. They are highly toxic components solely and highly expressed in the venom glands of snakes of the genus Atractaspis (Atractaspididae family).

Both endothelins and sarafotoxins act on the vascular system via identical ET-A (EDNRA) or ET-B (EDNRB) receptors.