Galanin is a neuropeptide with diverse biological activities. [1][2][3][4][5] It binds to rat galanin (GAL) receptor subtypes GAL1-3 (IC50s = 0.339, 1.35, and 3.31 nM, respectively) and human GAL1-3 (IC50s = 0.288, 1.62, and 12.3 nM, respectively). [1] Galanin binds to and inhibits contraction of guinea pig gastric smooth muscle cells induced by carbachol . [2] In vivo, Galanin (6 nmol, i.c.v.) increases feeding behavior in rats and increases latency to hindpaw withdrawal in response to heat and mechanical stimulation in a rat model of carrageenin-induced inflammation when administered at a dose of 2 nmol injected into the nucleus accumbens.[3][4] Galanin (5 μg, i.c.v.) also inhibits acetylcholine release induced by scopolamine in the ventral hippocampus of freely moving rats. [5]
Pituitary adenylate cyclase-activating peptide (PACAP) (6-27) is a PACAP receptor antagonist with IC50 values of 1,500, 600, and 300 nM, respectively, for rat PAC1, rat VPAC1, and human VPAC2 recombinant receptors expressed in CHO cells. It binds to PACAP receptors on SH-SY5Y and SK-N-MC human neuroblastoma and T47D human breast cancer cells (IC50s = 24.5, 106, and 105 nM, respectively) and inhibits cAMP accumulation induced by PACAP (1-38) (Kis = 457, 102, and 283 nM, respectively, in SH-SY5Y, SK-N-MC, and T47D cells). In vivo, in newborn pigs, PACAP (6-27) (10 μM) inhibits vasodilation of pial arterioles induced by PACAP (1-27) and PACAP (1-38) . It also inhibits PACAP (1-27)-stimulated increases in plasma insulin and glucagon levels and pancreatic venous blood flow in dogs when administered locally to the pancreas at a dose of 500 μg.
PAR2 (1-6) is a synthetic peptide agonist of proteinase-activated receptor 2 (PAR2) that corresponds to residues 1-6 of the amino terminal tethered ligand sequence of mouse and rat PAR2. It also corresponds to residues 39-44 and 37-42 of the mouse and rat full-length sequences, respectively. PAR2 (1-6) induces relaxation in precontracted rat arteries in a concentration-dependent manner, an effect that can be reduced by the nitric oxide synthase inhibitor L-NNA . It inhibits keratinocyte growth in the presence and absence of growth factors. PAR2 (1-6) inhibits LPS-induced pulmonary neutrophil influx and increases in matrix metalloproteinase-2 (MMP-2) activity in mice.
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
β-Amyloid (1-38), derived from mice and rats, is a chemical compound comprising 38 amino acids, specifically residues 1-38 of the Aβ peptide. Notably, it serves as the primary constituent of amyloid plaques associated with Alzheimer's disease.
Orphan GPCR SP9155 agonist P550 (mouse, rat) (26RFa (mouse, rat)) is an orphan GPCR with an orexigenic effect belonging to the RFamide peptide family. It acts as the cognate ligand for the mouse orphan receptor GPR103, which is also known as SP9155 or AQ27.