[Inhibitory effects of dipeptides containing tryptophan on the excitability on the giant neuron of the giant African snail (Achatina fulica, Ferussac)].
Besides an inhibitory effect of L-Lys-L-Phe-L-Tyr and L-Phe-L-Tyr, L-Phe-L-Trp showed the same effect on the excitability of a giant neurone (the TAN, tonically autoactive neurone) identified in suboesophageal ganglia of Achatina futica Férussac. The critical concentration of L-Phe-L-Trp to produce the effect was 10(-5)--3  X 10(-5) kg/1. The inhibitory effect of this substance was relatively slow and independent no chloride ions, as well as in the case of L-Phe-L-Tyr. L-Trp-L-Phe, Gly-L-Trp and L-Trp-Gly did not show any effect on the same neurone. The I-V curve of the TAN's neuromembrane, measured by the injection of a transmembrane triangular current, were not modified markedly by L-Phe-L-Trp at 4 X 10(-4) kg/1. The pattern of the TAN's spike firing produced by the depolarizing current injection were not influenced by this substance.
D000818:Animals; D004151:Dipeptides / Q000494:pharmacology*; D005724:Ganglia / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D012908:Snails / Q000502:physiology; D013329:Structure-Activity Relationship; D014364:Tryptophan / Q000494:pharmacology*
D004151:Dipeptides; D014364:Tryptophan
Effet inhibiteur de dipeptides contenant du tryptophanne sur l'excitabilité d'un neurone géant de l'escargot géant africain (Achatina fulica, Férussac).