GALANIN - A NEUROPEPTIDE WITH INHIBITORY ACTIONS

1. Galanin is a 29 (in humans 30) amino acids long neuropeptide with m ostly inhibitory, hyperpolarizing actions. 2. Differential structural requirements of truncated forms of galanin and differential agonist/an tagonist behaviour of chimeric peptides, high affinity galanin recepto r ligands suggest the presence of pharmacologically distinct galanin r eceptor subtypes. 3. The galanin receptor from human Bowes melanoma ce ll line-a member of G-protein coupled receptor superfamily-has been cl oned. 4. Galanin acts via G(i)/G(o) proteins inhibiting cAMP productio n, inositol phosphate turnover, opening K+ channels or closing Ca2+ ch annels.