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ABSTRACT: We investigated whether atorvastatin has beneficial hemodynamic effects during acute pulmonary thromboembolism (APT) and whether sildenafil improves these effects. We studied the involvement of oxidative stress, matrix metalloproteinases (MMPs), and neutrophil activation. APT was induced with autologous blood clots (500 mg/kg) in anesthetized male lambs pretreated with atorvastatin (10 mg/kg/day, subcutaneously; 1 week) or vehicle (dimethyl sulfoxide 10% subcutaneously). Sildenafil (0.7 mg/kg intravenously) or saline infusions were performed 60 min after APT induction. Non-embolized control animals received saline. APT significantly increased pulmonary vascular resistance index (PVRI) and mean pulmonary artery pressure (MPAP) by approximately 310% and 258% respectively. While atorvastatin pretreatment attenuated these increases (~150% and 153%, respectively; P < 0.05), its combination with sildenafil was associated with lower increases in PVRI and MPAP (~32% and 36%, respectively). Gelatin zymography showed increased MMP-9 and MMP-2 levels in the bronchoalveolar lavage, and increased MMP-9 levels in plasma from embolized animals. Atorvastatin pretreatment attenuated bronchoalveolar lavage MMP-2 increases. The combination of drugs blunted the MMPs increases in bronchoalveolar lavage and plasma (P < 0.05). Neutrophils accumulated in bronchoalveolar lavage after APT, and atorvastatin pretreatment combined with sildenafil (but not atorvastatin alone) attenuated this effect (P < 0.05). APT increased lung lipid peroxidation and total protein concentrations in bronchoalveolar lavage, thus indicating oxidative stress and alveolar-capillary barrier damage, respectively. Both increases were attenuated by atorvastatin pretreatment alone or combined with sildenafil (P < 0.05). We conclude that pretreatment with atorvastatin protects against the pulmonary hypertension associated with APT and that sildenafil improves this response. These findings may reflect antioxidant effects and inhibited neutrophils/MMPs activation.
European journal of pharmacology 09/2011; 670(2-3):554-60. · 2.59 Impact Factor
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Paula G Czaikoski,
Danilo L Menaldo,
Silvana Marcussi,
Anne L C Baseggio,
André L Fuly,
Rafael C Paula,
Andreza U Quadros,
Pedro R T Romão,
Maria L T Buschini,
Fernando Q Cunha,
Andreimar M Soares,
Marta C Monteiro
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ABSTRACT: Previous studies have shown that venoms of social wasps and bees exhibit strong anticoagulant activity. The present study describes the anticoagulant and fibrinogen-degrading pharmacological properties of the venom of Polybia occidentalis social wasp. The results demonstrated that this venom presented anticoagulant effect, inhibiting the coagulation at different steps of the clotting pathway (intrinsic, extrinsic and common pathway). The venom inhibited platelet aggregation and degraded plasma fibrinogen, possibly containing metal-dependent metalloproteases that specifically cleave the Bβ-chain of fibrinogen. In conclusion, fibrinogenolytic and anticoagulant properties of this wasp venom find a potential application in drug development for the treatment of thrombotic disorders. For that, further studies should be carried out in order to identify and isolate the active compounds responsible for these effects.
Blood coagulation & fibrinolysis: an international journal in haemostasis and thrombosis 10/2010; 21(7):653-9. · 1.25 Impact Factor
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Paula G Czaikoski,
Danilo L Menaldo,
Silvana Marcussi,
Anne LC Baseggio,
André L Fuly,
Rafael C Paula,
Andreza U Quadros,
Pedro RT Romão,
Maria LT Buschini,
Fernando Q Cunha,
Andreimar M Soares,
Marta C Monteiro
[show abstract]
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ABSTRACT: Previous studies have shown that venoms of social wasps and bees exhibit strong anticoagulant activity. The present study describes the anticoagulant and fibrinogen-degrading pharmacological properties of the venom of Polybia occidentalis social wasp. The results demonstrated that this venom presented anticoagulant effect, inhibiting the coagulation at different steps of the clotting pathway (intrinsic, extrinsic and common pathway). The venom inhibited platelet aggregation and degraded plasma fibrinogen, possibly containing metal-dependent metalloproteases that specifically cleave the Bβ-chain of fibrinogen. In conclusion, fibrinogenolytic and anticoagulant properties of this wasp venom find a potential application in drug development for the treatment of thrombotic disorders. For that, further studies should be carried out in order to identify and isolate the active compounds responsible for these effects.
Blood Coagulation and Fibrinolysis 09/2010; 21(7):653–659. · 1.24 Impact Factor
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Fernando Spiller,
Maria I L Orrico,
Daniele C Nascimento, Paula G Czaikoski,
Fabrício O Souto,
José C Alves-Filho,
Andressa Freitas,
Daniela Carlos,
Marcelo F Montenegro,
Alberto F Neto,
Sergio H Ferreira,
Marcos A Rossi,
John S Hothersall,
Jamil Assreuy,
Fernando Q Cunha
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ABSTRACT: Recovering the neutrophil migration to the infectious focus improves survival in severe sepsis. Recently, we demonstrated that the cystathionine gamma-lyase (CSE)/hydrogen sulfide (H(2)S) pathway increased neutrophil recruitment to inflammatory focus during sterile inflammation.
To evaluate if H(2)S administration increases neutrophil migration to infectious focus and survival of mice.
Sepsis was induced by cecal ligation and puncture (CLP). Measurements and Main Results: The pretreatments of mice with H(2)S donors (NaHS or Lawesson's reagent) improved leukocyte rolling/adhesion in the mesenteric microcirculation as well as neutrophil migration. Consequently, bacteremia levels were reduced, hypotension and lung lesions were prevented, and the survival rate increased from approximately 13% to approximately 80%. Even when treatment was delayed (6 h after CLP), a highly significant reduction in mortality compared with untreated mice was observed. Moreover, H(2)S pretreatment prevented the down-regulation of CXCR2 and l-selectin and the up-regulation of CD11b and G protein-coupled receptor kinase 2 in neutrophils during sepsis. H(2)S also prevented the reduction of intercellular adhesion molecule-1 expression in the endothelium of the mesenteric microcirculation in severe sepsis. Confirming the critical role of H(2)S on sepsis outcome, pretreatment with dl-propargylglycine (a CSE inhibitor) inhibited neutrophil migration to the infectious focus, enhanced lung lesions, and induced high mortality in mice subjected to nonsevere sepsis (from 0 to approximately 80%). The beneficial effects of H(2)S were blocked by glibenclamide (a ATP-dependent K(+) channel blocker).
These results showed that H(2)S restores neutrophil migration to the infectious focus and improves survival outcome in severe sepsis by an ATP-dependent K(+) channel-dependent mechanism.
American Journal of Respiratory and Critical Care Medicine 03/2010; 182(3):360-8. · 11.08 Impact Factor
