Bv8, a small protein from frog skin and its homologue from snake venom induce hyperalgesia in rats

From skin secretions of Bombina variegata and Bombina bombina, we isolated a small protein termed Bv8, The sequence of its 77 amino acids was establis hed by peptide analysis and by cDNA cloning of the Bv8 precursor. Bv8 stimu lates the contraction of the guinea-pig ileum at nanomolar concentrations. The contraction is nor inhibited by a variety of antagonist. Injection of a few micrograms of Bv8 into the brain of rats elicits, as assessed by the t ail-flick rest and paw pressure threshold, a marked hyperalgesia which last s for about 1 h. Bv8 is related to protein A, a component of the venom of t he black; mamba. After i.c.v. injection, protein A is even more active than Bv8 in inducing hyperalgesia. (C) 1999 Elsevier Science B.V. All rights re served.