Portal de Periódicos da CAPES

Artigo Acesso aberto Produção Nacional Revisado por pares

BIBTEX RIS

Inhibition of acute nociceptive responses in rats after i.c.v. injection of Thr 6 ‐bradykinin, isolated from the venom of the social wasp, Polybia occidentalis

2007; Wiley; Volume: 151; Issue: 6 Linguagem: Inglês

10.1038/sj.bjp.0707275

1476-5381

Márcia Renata Mortari, Alexandra Olímpio Siqueira Cunha, Ruither Oliveira Gomes Carolino, Joaquim Coutinho‐Netto, José Carlos Tomaz, Norberto Peporine Lopes, Norberto Cysne Coimbra, Wagner Ferreira dos Santos,

Healthcare and Venom Research

In this work, a neuroactive peptide from the venom of the neotropical wasp Polybia occidentalis was isolated and its anti-nociceptive effects were characterized in well-established pain induction models.Wasp venom was analysed by reverse-phase HPLC and fractions screened for anti-nociceptive activity. The structure of the most active fraction was identified by electron-spray mass spectrometry (ESI-MS/MS) and it was further assessed in two tests of anti-nociceptive activity in rats: the hot plate and tail flick tests.The most active fraction contained a peptide whose structure was Arg-Pro-Pro-Gly-Phe-Thr-Pro-Phe-Arg-OH, which corresponds to that of Thr(6)-BK, a bradykinin analogue. This peptide was given by i.c.v. injection to rats. In the tail flick test, Thr(6)-BK induced anti-nociceptive effects, approximately twice as potent as either morphine or bradykinin also given i.c.v. The anti-nociceptive activity of Thr(6)-BK peaked at 30 min after injection and persisted for 2 h, longer than bradykinin. The primary mode of action of Thr(6)-BK involved the activation of B(2) bradykinin receptors, as anti-nociceptive effects of Thr(6)-BK were antagonized by a selective B(2) receptor antagonist.Our data indicate that Thr(6)-BK acts through B(2) bradykinin receptors in the mammalian CNS, evoking antinociceptive behaviour. This activity is remarkably different from that of bradykinin, despite the structural similarities between both peptides. In addition, due to the increased metabolic stability of Thr(6)-BK, relative to that of bradykinin, this peptide could provide a novel tool in the investigation of kinin pathways involved with pain.