Bioactive peptides isolated from the body wall of the sea cucumber <i>Apostichopus japonicus</i>.

Sequences of twenty peptides isolated from the body wall of the sea cucumber Apostichopus japonicus that affect the contractile activity of the radial longitudinal muscle (RLM) and/or the intestine. Four of the peptides also affect the stiffness of the collagenous body wall. Key: I, inhibition of electrically-induced contraction; P, potentiation of electrically-induced contraction; C, contraction; R, relaxation.; IA, inhibition of acetylcholine-induced stiffening. (Iwakoshi et al., 1995; Birenheide et al., 1998; Ohtani et al., 1999).