Structural requirements for galanin action in the guinea-pig ileum.
Galanin fragments and galanin analogues were tested on neurally evoked muscle contractions in guinea-pig ileum in vitro. Galanin fragments inhibited the neurally evoked circular muscle contractions with the following order of potency: Galanin(1-29), galanin(2-29), galanin(1-15). In contrast, galanin(3-29), galanin(10-29), galanin(21-29), [D-Trp2]galanin, [Phe2]galanin and [Tyr2]galanin were ineffective. Galanin(1-29), galanin(2-29) and galanin(1-15) did not affect the neurally evoked longitudinal muscle contractions. These results indicate that (1) the two N-terminal amino acid residues of the galanin molecule are essential for the inhibitory action of galanin on neurally-evoked circular muscle contraction and (2) for the full potency also the C-terminal end is required.
Department of Molecular Physiology, National Institute for Physiological Sciences, Okazaki, Japan.
A
A
Kuwahara
T
T
Ozaki
N
N
Yanaihara
D000704:Analysis of Variance; D000818:Animals; D019004:Galanin; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects / Q000294:innervation; D010446:Peptide Fragments / Q000494:pharmacology; D010455:Peptides / Q000138:chemical synthesis / Q000494:pharmacology*; D013329:Structure-Activity Relationship
D010446:Peptide Fragments; D010455:Peptides; D019004:Galanin