EN
Galanin (GAL) is a 29-amino-acid residue peptide originally isolated from porcine upper small intestine. GAL exhibits various physiological activities, such as effects on hormones release, smooth muscles contractions, gastric acid secretion, neurons degeneration and feeding. One of the biological actions of GAL is the inhibition of insulin secretion from the pancreatic ß-cells. In our studies we have designed several new 15-amino-acid-residue galanin fragment analogues modified in positions: 6, 8, 9, 10, 11 and tested for their effects on glucose-induced insulin secretion from isolated rat pancreatic islets of Langerhans. In vitro insulin secretion was studied during static incubation. All peptides were tested at two concentrations: 0.1 µM and 1 µM. Among the analogues derived from GAL(1-15)NH2 peptide: [Phe9]GAL(1-15)NH2 and [Pro11]GAL(1-15)NH2 were found to be the potent antagonists against the inhibitory effect of GAL on glucose-induced insulin secretion from the isolated rat pancreas. These analogues block the GAL-mediated inhibition of insulin secretion. The present studies have shown that analogues: [Phe9]GAL(1-15)NH2 and [Pro11]GAL(1-15)NH2 may be a key compounds for developing a more potent GAL antagonists.