Table 1. Bioactive peptides isolated from the body wall of the sea cucumber Apostichopus japonicus.
| Peptide name | Peptide sequence | Effect on RLM | Effect on intestine | Effect on body wall |
| Sticho-MFamide-1 | GYSPFMFamide | No effect | R | - |
| Sticho-MFamide-2 | FKSPFMFamide | No effect | R | - |
| NGIWYamide | NGIWYamide | C | C | stiffening |
| Stichopin | DRQGWPACYDSKGNYKC | I | No effect | IA |
| GN-19 | GGRLPNYAGPPRMPWLIHN | No effect | C or R | - |
| GLRFA | GLRFA | P | C | - |
| Holokinin-1 | PLGYMFR | I | C | softening |
| Holokinin-2 | PLGYM(O)FR | I | C | softening |
| Holokinin-3 | PLGY(Br)M(O)FR | I | C | - |
| Holokinin-1 (3–7) | GYMFR | I | C | - |
| SWYG-1 | SWYGSLG | I or P | No effect | - |
| SWYG-2 | SWYGTLG | I or P | No effect | - |
| SWYG-3 | SWYGSLA | I | No effect | - |
| - | GYI | I | - | - |
| KIamide-9 | KHKTAYTGIamide | I | C | - |
| - | GYWKDLDNYVKAHKT | I | - | - |
| - | MPMNPADYFSRGTVYIPTRDS | P | - | - |
| - | GPSANSFTYGRCADDRC | P | - | - |
| - | KGKQKGAGRGKGN | P | - | - |
| - | APHAIRPPSG | 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).