Author(s): Sousa, Paulo Cesar P. ; Brito, Teresinha S. ; Freire, Daniel S. ; Ximenes, Rafael M. ; Magalhaes, Pedro Jorge C. ; Monteiro, Helena S. A. ; Alves, Renata S. ; Martins, Alice Maria C. ; Toyama, Daniela O. ; Toyama, Marcos H. [UNESP]
Date: 2014
Persistent ID: http://hdl.handle.net/11449/113090
Origin: Oasisbr
Subject(s): Apis mellifera; Venom; Mellitin; Phospholipase A(2); Aorta
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Cearense Foundation for Research Support (FUNCAP)
Background: Apis mellifera stings are a problem for public health worldwide, particularly in Latin America due to the aggressiveness of its Africanized honeybees. Massive poisoning by A. mellifera venom (AmV) affects mainly the cardiovascular system, and several works have described its actions on heart muscle. Nevertheless, no work on the pharmacological action mechanisms of the AmV in isolated aorta has been reported. Thus, the present work aimed to investigate the actions of AmV and its main fractions, phospholipase A(2) (PLA(2)) and melittin, on isolated aorta rings and a probable action mechanism.Results: AmV and the complex PLA(2) + melittin (0.1-50 mu g/mL) caused contraction in endothelium-containing aorta rings, but neither isolated PLA(2) nor melittin were able to reproduce the effect. Endothelium removal did not change the maximum vasoconstrictor effect elicited by AmV. CA(2+)-free medium, as well as treatment with phentolamine (5 mu M), verapamil (10 mu M), losartan (100 mu M), and U-73122 (10 mu M, a phospholipase C inhibitor), eliminated the AmV-induced contractile effects.Conclusions: In conclusion, AmV caused contractile effect in aorta rings probably through the involvement of voltage-operated calcium channels, AT1 and alpha-adrenergic receptors via the downstream activation of phospholipase C. The protein complex, PLA(2) + melittin, was also able to induce vasoconstriction, whereas the isolated proteins were not.
Univ Fed Ceara, Dept Physiol & Pharmacol, Fortaleza, Ceara, Brazil
Univ Fed Ceara, Dept Clin & Toxicol Anal, Fortaleza, Ceara, Brazil
Univ Prebiteriana Mackenzie, Ctr Biol & Hlth Sci, Sao Paulo, Brazil
Sao Paulo State Univ, UNESP, Univ Estadual Paulista, Sao Vicente, SP, Brazil
Univ Fed Pernambuco, Dept Antibiot, Recife, PE, Brazil
Sao Paulo State Univ, UNESP, Univ Estadual Paulista, Sao Vicente, SP, Brazil
