Rohdei-litorin: a new peptide from the skin of Phyllomedusa rohdei.

The bombesin-litorin family of peptides is characterized by the common amino acid sequence-Gly-His-X-Met-NH2 at the C-terminus, where X is a hydrophobic or aromatic residue. A new member of this family, rohdei-litorin, has been isolated from amphibian skin and its structure shown to be: Glp-Leu-Trp-Ala-Thr-Gly-His-Phe-Met-NH2. This new peptide displayed a greater affinity than other members of the family for rat urinary bladder receptors. A litorin-like peptide, with high affinity for this kind of receptor, has already been described in mammalian spinal cord and named neuromedin B. Rohdei-litorin shares with neuromedin B the entire C-terminal octrapeptide and may be considered the amphibian counterpart of this mammalian neuropeptide.