Litorin is a peptide originally isolated from L. aurea that has diverse biological activities.1,2,3,4 It is an agonist of the gastrin-releasing peptide receptor (GRPR) and the neuromedin B (NMB) receptor in BALB/c 3T3 fibroblasts expressing the human receptors (EC50s = 0.44 and 0.03 nM, respectively) and binds to frog bombesin receptor subtype 4 (BB4) in CHO-K1 cells (Ki = 1.2 nM).2,3 Litorin (10-100 ng/kg) induces contractions of isolated guinea pig gallbladder.4 It decreases food intake in rats when administered at doses ranging from 4 to 128 µg/kg.1
1.Kulkosky, P.J., and Gibbs, J.Litorin suppresses food intake in ratsLife Sci.31(7)685-692(1982) 2.Uehara, H., GonzÁlez, N., Sancho, V., et al.Pharmacology and selectivity of various natural and synthetic bombesin related peptide agonists for human and rat bombesin receptors differsPeptides32(8)1685-1699(2011) 3.Katsuno, T., Pradhan, T.K., Ryan, R.R., et al.Pharmacology and cell biology of the bombesin receptor subtype 4 (BB4-R)Biochemistry38(22)7307-7320(1999) 4.Endean, R., Erspamer, V., Falconieri Erspamer, G., et al.Parallel bioassay of bombesin and litorin, a bombesin-like peptide from the skin of Litoria aureaBr. J. Pharmacol.55(2)213-219(1975)