Lectina de Amansia multifida Lamouroux: especificidade fina por carboidratos e ação farmacológica

• Autor(a) principal: Neves, Samya de Araújo
• Data de Publicação: 2005
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
• Texto Completo: http://www.repositorio.ufc.br/handle/riufc/15648
• topic: Lectina; Amansia multifida; Carboidratos; Nocicepção; Inflamação

This study aimed to investigate the specificity for simple sugars or glycoproteins of the lectin from the red seaweed Amansia multifida. The interaction kinetics in real time of the soluble lectin with several immobilized glycoproteins and the inhibition of these interactions by oligomanosides were analyzed through surface plasmon resonance technology. The lectin showed somehow preference to the monosaccharide mannose and its interaction with di-tri and pentamanosides was more expressive. The lectin of A. multifida interacted with glycopeptides Man5 to Man8– asparagine, and the high affinity of the lectin for these structures was shown by analyzing the interaction with glycoproteins such as ribonuclease b and bovine lactotransferrin. The results obtained with Sepharose6B column containing immobilized A. multifida and the low recognition of soybean agglutinin corroborate the non-recognition of Man 9, and discard the capacity of association with a structure showing three residues of mannose linked in a-1,2 at the glycan extremity. The results of the pharmacological studies with three models of pain showed that A. multifida lectin caused analgesia. In the abdominal contorsion and formalin tests a dose-dependent effect was observed. The IP route was more effective than the oral route. In order to compare the analgesic action of A. multifida lectin with that of morfine, a narcotic with central action, the hot plate test was conducted after pre-treatment with the opioid antagonist naloxane. The antinociceptive effect of the lectin was reduced at the presence of naloxane, which suggests that its action involves activation of opioid receptors as occurs with morfine. An antinociceptive effect at central level was also observed when the lectin increased the duration of barbituric-induced sleep. The lectin showed anti-inflammatory action by the paw edema test with carrageenan and dextran. The involvement of the lectin in the observed antinociceptive effects was assessed by pre-treatment with D-mannose and avidin. The antinociceptive effect was suppressed by D-mannose. A. multifida lectin was shown to have antinociceptive properties of both central and peripheral origin, being these effects more evident for pain of inflammatory origin