Crustacean cardioactive peptide，free acid

Crustacean cardioactive peptide，free acid is a highly conserved， amidated cyclic nonapeptide， first isolated from the pericardial organs of the shore crab Carcinus maenas， where it has a role in regulating heartbeat; Crustacean cardioactive peptide，free acid also modulates the neuronal activity in other arthropods.