eledoisin

[ĕl′ĭ-doisĭn]
n.
  1. A protein that is formed in the venom gland of several species of octopuses and is used as a vasodilator and a contraction agent of extravascular smooth muscle.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.