Wj. Rossowski et al., GALANIN - STRUCTURE-DEPENDENT EFFECT ON PANCREATIC AMYLASE SECRETION AND JEJUNAL STRIP CONTRACTION, European journal of pharmacology, 240(2-3), 1993, pp. 259-267
Rat and porcine galanin and their fragments inhibited cholecystokinin-
8 (CCK-8)-stimulated amylase secretion with the following activities:
rat galanin-(1-29) = porcine galanin-(1-29) = galanin-(1-15) = rat gal
anin-(3-29) > rat galanin-(2-29) = porcine galanin-(2-29) > galanin-(1
-10). Fragments of rat galanin-(9-29) and N(alpha)-acetyl-galanin-(9-2
9) were able to inhibit CCK-8-stimulated pancreatic amylase secretion
but only at higher dose levels. Porcine galanin-(15-29) and rat galani
n-(21-29) were unable to produce significant inhibition. Rat and porci
ne galanin-(1-29), galanin-(1-15) and rat N(alpha)-acetyl-galanin-(9-2
9) also inhibited basal pancreatic amylase secretion. In the rat jejun
al strip contraction model, rat galanin-(1-29) and porcine galanin-(1-
29) have similar potencies. Galanin-(1-15) and galanin-(1-10) stimulat
e rat jejunal strip contraction with decreasing potencies. Elimination
of Gly1 from the N-terminus of both rat and porcine galanin had no si
gnificant effect either on pancreatic amylase secretion or on jejunal
strip contraction. The rat galanin-(3-29) and (9-29) are not active in
the stimulation of rat jejunal strip contraction. Acetylation of porc
ine galanin-(9-29) created a peptide that was a powerful stimulator of
rat jejunal strip contraction. The present data indicate that N-termi
nal rat galanin amino acid residues are crucial for rat jejunal strip
contraction but are not required for inhibition of pancreatic amylase.
These results suggest that the galanin amino acid sequence contains s
everal specific domains, which can be recognized by specific galanin r
eceptor subsets.