title: Evaluation of Thr6-bradykinin purified from Polybia occidentalis wasp venom in the choline uptake of mammal cortices.
abstract: BACKGROUND
  Thr6-bradykinin is a peptide found in the venom of social and solitary wasps. This kinin, along with other bradykinin-like peptides, is known to cause irreversible paralysis in insects by presynaptic blockade of cholinergic transmission. However, this activity has never been tested in mammals.
  
  
  OBJECTIVE
  As such, the objective of this study was to evaluate the effect of Thr6-bradykinin on the cholinergic system of rats.
  
  
  METHODS
  The peptide was isolated from the venom of the Neotropical social wasp Polybia occidentalis Olivier (Vespidae). After correct identification and quantification by ESI-MS and MS/MS, the peptide was tested in [14C]-choline uptake using rat cortical synaptosomes. Each uptake assay was accompanied by lactic acid dehydrogenase (LDH) activity measurement to evaluate synaptosome integrity in the presence of six increasing concentrations of BK or Thr6-BK (0.039, 0.156, 0.625, 2.500, 10.000 and 40.000 μM).
  
  
  RESULTS
  Data revealed that neither BK nor Thr6-BK at any of the six concentrations tested (from 0.039 to 40.000 μM) affected [14C]-choline uptake in synaptosomes. Moreover, there was no increase in LDH in the supernatants, indicating that BK and Thr6-BK did not disrupt the synaptosomes.
  
  
  CONCLUSIONS
  In contrast to previous reports for the insect central nervous system (CNS), Thr6-BK had no effect on mammalian cholinergic transmission. Nevertheless, this selectivity for the insect CNS, combined with its irreversible mode of action may be relevant to the discovery of new sources of insecticides and could contribute to understanding the role of kinins in the mammalian CNS.
authors: a Neuropharmacology Laboratory, Department of Physiological Sciences , Institute of Biological Sciences, University of Brasília , Brasília , Brazil.
authors: Márcia Renata
authors: MR
authors: Mortari
authors: d Neurobiology and Venoms Laboratory, Department of Biology, College of Philosophy, Sciences and Literature of Ribeirão Preto , University of São Paulo , São Paulo , Brazil.
authors: Alexandra Olimpio Siqueira
authors: AO
authors: Cunha
authors: b Department of Biochemistry and Immunology, School of Medicine of Ribeirão Preto , University of São Paulo , São Paulo , Brazil.
authors: Ruither Oliveira Gomes
authors: RO
authors: Carolino
authors: a Neuropharmacology Laboratory, Department of Physiological Sciences , Institute of Biological Sciences, University of Brasília , Brasília , Brazil.
authors: Juliana de Castro E
authors: JC
authors: Silva
authors: c Organic Chemistry Laboratory, Department of Physics and Chemistry, Faculty of Pharmaceutical Sciences of Ribeirão Preto , University of São Paulo , São Paulo , Brazil.
authors: Norberto Peporine
authors: NP
authors: Lopes
authors: d Neurobiology and Venoms Laboratory, Department of Biology, College of Philosophy, Sciences and Literature of Ribeirão Preto , University of São Paulo , São Paulo , Brazil.
authors: Wagner Ferreira Dos
authors: WF
authors: Santos
mesh_terms: D000818:Animals; D001920:Bradykinin / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D002250:Carbon Radioisotopes / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D002794:Choline / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical / Q000379:methods; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014862:Wasp Venoms / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D014863:Wasps
chemical_list: D002250:Carbon Radioisotopes; D014862:Wasp Venoms; D002794:Choline; D001920:Bradykinin
keywords: Social wasp venom; bradykinin-related peptide; neuroactive peptides