The expansion behaviour of sea anemones may be coordinated by two inhibitory neuropeptides, Antho-KAamide and Antho-RIamide.
Antho-KAamide (L-3-phenyllactyl-Phe-Lys-Ala-NH2) and Antho-RIamide (L-3-phenyllactyl-Tyr-Arg-Ile-NH2) are novel neuropeptides isolated from the sea anemone Anthopleura elegantissima. They both inhibited spontaneous contractions of isolated muscle preparations from a wide variety of anemone species (threshold around 10(-7) M). Their actions were universal in that they inhibited every muscle preparation tested, regardless of whether the muscle group was located in the ectoderm or endoderm, or was oriented in a circular or longitudinal direction. Injection of Antho-KAamide or Antho-RIamide into the coelenteron of intact sea anemones resulted in a marked expansion of the animals. Similar shape changes followed feeding or exposure to soluble food extracts. Therefore, we hypothesize that nerve cells that release Antho-KAamide and Antho-RIamide are involved in the expansion phase of feeding behaviour in sea anemones.
Department of Applied Biology, University of Hull, U.K.
I D
ID
McFarlane
D
D
Hudman
H P
HP
Nothacker
C J
CJ
Grimmelikhuijzen
D000818:Animals; D004558:Electric Stimulation; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009132:Muscles / Q000187:drug effects / Q000502:physiology*; D009479:Neuropeptides / Q000302:isolation & purification / Q000494:pharmacology*; D009842:Oligopeptides / Q000302:isolation & purification / Q000494:pharmacology*; D012615:Sea Anemones / Q000187:drug effects / Q000502:physiology*; D013045:Species Specificity
D009479:Neuropeptides; D009842:Oligopeptides; C071055:3-phenyllactyl-phenylalanyl-lysyl-alaninamide; C074612:Antho-RIamide I