The actions of Caenorhabditis elegans neuropeptide-like peptides (NLPs) on body wall muscle of Ascaris suum and pharyngeal muscle of C. elegans.
The actions of six Neuropeptide-like Peptides (NLPs) were investigated on Ascaris suum dorsal body wall muscle and Caenorhabditis elegans pharyngeal muscle. The NLPs tested on A. suum muscle, viz, NLP-1A, NLP-2A and B, had no direct effect on the muscle but all reversibly reduced acetylcholine (ACh)-induced contractions of the muscle, NLP-2A being the most potent, with an IC50 value of 78 microM. NLP-2A also reversibly reduced ACh-induced depolarizations of A. suum muscle resting membrane potential. NLP-1A, NLP-2A, NLP-3C and NLP-10A all increased pharyngeal pumping in C. elegans, NLP-8A weakly inhibited pumping while NLP-2B was inactive. NLP-10A induced a concentration-dependent increase in pumping activity with a threshold of 10-100 nM. Since genes encoding NLPs (nlp genes) are expressed in C. elegans pharyngeal neurons it is likely these peptides play a role in feeding behaviour.
Papaioannou
Sylvana
S
School of Biological Sciences, University of Southampton, Southampton, UK.
Holden-Dye
Lindy
L
Walker
R J
RJ
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001200:Ascaris / Q000187:drug effects / Q000502:physiology*; D017173:Caenorhabditis elegans / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D017238:Genes, Helminth; D008564:Membrane Potentials / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D009132:Muscles / Q000187:drug effects / Q000502:physiology; D009479:Neuropeptides / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D010609:Pharyngeal Muscles / Q000187:drug effects / Q000502:physiology
D029742:Caenorhabditis elegans Proteins; D009479:Neuropeptides; D000109:Acetylcholine