Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/198013
Type: Artigo de periódico
Title: Inhibitory Effects Of Staphylococcal Enterotoxin Type B On Human Platelet Adhesion In Vitro.
Author: Morganti, Rafael P
Marcondes, Sisi
Baldasso, Paulo A
Marangoni, Sergio
De Nucci, Gilberto
Antunes, Edson
Abstract: Septic shock was formerly recognized as a consequence of Gram-negative bacteraemia, but at present the incidence of Gram-positive sepsis seems to be more relevant, contributing for more than 50% of cases. Staphylococcal aureus can induce toxic shock in humans through the production of potent toxins termed Staphylococcal enterotoxins, from which Staphylococcal enterotoxin type B (SEB) is one of most studied. Platelets are reported to participate in pathogenesis of severe sepsis, but the exact role of platelets in this event is poorly investigated, particularly that caused by Gram-positive bacteria. Therefore, we have used the model of platelet adhesion to fibrinogen-coated plates to investigate the actions of SEB on human platelets. Ninety-six-well microtiter plates were coated with human fibrinogen (50 microg/mL), and human washed platelet suspension (6 x 10(6) platelets) was added to each well. Adherent platelets were quantified through measurement of acid phosphatase activity. Staphylococcal enterotoxin B (0.0001-30 microg/mL, incubated for 5 to 60 min) time- and dose-dependently inhibited platelet adhesion. This response was modified neither by the protein synthesis inhibitor puromycin (0.01 and 0.1 mM) nor by the superoxide scavengers superoxide dismutase (SOD, 100 units/mL) and polyethylene glycol-SOD (30 U/mL). The peroxide hydrogen (H(2)O(2)) scavenger catalase polyethylene glycol (1000 U/mL) significantly attenuated the platelet adhesion inhibition by SEB. The cAMP and cGMP levels were not changed by SEB (0.0001-30 microg/mL, 60 min). Our findings suggest that H(2)O(2) at least partly contributes to the inhibitory responses of human platelet adhesion by SEB.
Subject: Acid Phosphatase
Animals
Blood Platelets
Catalase
Cattle
Cell Survival
Chromatography, High Pressure Liquid
Enterotoxins
Humans
Nucleotides, Cyclic
Platelet Adhesiveness
Platelet Aggregation
Polyethylene Glycols
Puromycin
Superoxide Dismutase
Rights: fechado
Identifier DOI: 10.1080/09537100802236035
Address: http://www.ncbi.nlm.nih.gov/pubmed/18925511
Date Issue: 2008
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

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