Galanin (2-11) amide is a synthetic peptide fragment of the neuropeptide galanin and an agonist of the galanin-2 (GAL2) receptor (EC50= 9.32 nM in a fluorescence imaging plate reader assay).1It selectively binds to the GAL2receptor (IC50= 1.76 nM for the rat receptor) over the GAL1receptor (IC50= 879 nM for the human receptor) but does also bind to the GAL3receptor (Ki= 271 nM for the rat receptor).1,2Intracerebroventricular administration of galanin (2-11) amide (1 nmol/animal) decreases immobility in the forced swim test in rats.3It also reduces the hind paw mechanical pain threshold and increases the hind paw cold sensitivity threshold in rats.1
Spexin TFA, a potent agonist for galanin receptor 2 3 (GAL2GAL3) with EC50 values of 45.7 and 112.2 nM respectively, shows no significant activity towards galanin receptor 1. As an endogenous peptide promoting satiety, it reduces long chain fatty acid uptake by adipocytes and lowers food consumption in diet-induced obese mice and rats. Additionally, it moderates LH secretion in goldfish and demonstrates anxiolytic effects in vivo.
Potent and selective galanin receptor 2 (GAL2) agonist (EC50 = 38 nM, Ki values are 6.55, 497 and 587 nM at GAL2, GAL3 and GAL1 respectively). Has an additive effect on the signal transduction of galanin.
Potent, non-selective galanin receptor antagonist (Ki values are 1.82 and 5.1 nM at GAL1 and GAL2 respectively) that inhibits galanin (1-29) binding in rat brain in vitro (IC50 = 3 - 15 nM). Attenuates the antidepressant effects of fluoxetine and blocks galanin-induced food intake in vivo. Also exhibits weak partial agonist activity at peripheral GAL2 receptors at doses > 100 nM.
Selective galanin GAL1 receptor agonist (Ki values are 0.23 and 5.71 nM for GAL1 and GAL2 receptors respectively). Enhances food consumption in rats following i.c.v. administration and reduces CAP-induced inflammatory pain.
Selective galanin GAL2 receptor antagonist (Ki values are 13.1 and 420 nM for GAL2 and GAL1 receptors respectively). Blocks the pro-nociceptive effect of GAL2 receptor agonists.
Non-selective galanin receptor agonist (Ki values are 0.98, 1.48 and 1.47 nM for GAL1, GAL2 and GAL3 respectively). Anticonvulsant; prevents the occurrence of full kindled seizures in rats.