RESUMO
This study investigated the efficacy of terutroban, a specific thromboxane/prostaglandin endoperoxide receptor antagonist, on stroke incidence in spontaneously hypertensive stroke-prone rats (SHRSP). The effects of terutroban were compared with those of aspirin, another antiplatelet agent, and rosuvastatin, known to exert end-organ protection in SHRSP. Salt-loaded male SHRSP were treated orally once a day with vehicle, terutroban (30 mg/kg/day), aspirin (60 mg/kg/day), or rosuvastatin (10 mg/kg/day). Compared with vehicle, and regardless of any effect on blood pressure or serum thromboxane B(2) levels, terutroban significantly increased survival (p < 0.001) as a consequence of a delayed brain lesion occurrence monitored by magnetic resonance imaging (p < 0.001), and a delayed increase of proteinuria (p < 0.001). Terutroban decreased cerebral mRNA transcription of interleukin-1beta, transforming growth factor-beta, and monocyte chemoattractant protein-1 after 6 weeks of dietary treatment. Terutroban also prevented the accumulation of urinary acute-phase proteins at high molecular weight, identified as markers of systemic inflammation, and assessed longitudinally by one-dimensional electrophoresis. Terutroban also has protective effects on the vasculature as suggested by the preservation of endothelial function and endothelial nitric-oxide synthase expression in isolated carotid arteries. These effects are similar to those obtained with rosuvastatin, and superior to those of aspirin. Terutroban increases survival in SHRSP by reducing systemic inflammation as well as preserving endothelial function. These data support clinical development of terutroban in the prevention of cerebrovascular and cardiovascular complications of atherothrombosis.
Assuntos
Endotélio Vascular/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Naftalenos/uso terapêutico , Propionatos/uso terapêutico , Substâncias Protetoras/uso terapêutico , Receptores de Prostaglandina/antagonistas & inibidores , Receptores de Tromboxanos/antagonistas & inibidores , Acidente Vascular Cerebral/prevenção & controle , Síndrome de Resposta Inflamatória Sistêmica/prevenção & controle , Animais , Aspirina/administração & dosagem , Aspirina/farmacologia , Aspirina/uso terapêutico , Biomarcadores/análise , Biomarcadores/sangue , Biomarcadores/urina , Pressão Sanguínea/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/imunologia , Encéfalo/patologia , Endotélio Vascular/imunologia , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiopatologia , Fluorbenzenos/administração & dosagem , Fluorbenzenos/farmacologia , Fluorbenzenos/uso terapêutico , Hipertensão/complicações , Hipertensão/imunologia , Hipertensão/metabolismo , Hipertensão/patologia , Imageamento por Ressonância Magnética , Masculino , Naftalenos/administração & dosagem , Naftalenos/farmacologia , Propionatos/administração & dosagem , Propionatos/farmacologia , Substâncias Protetoras/administração & dosagem , Substâncias Protetoras/farmacologia , Pirimidinas/administração & dosagem , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Ratos , Ratos Endogâmicos SHR , Rosuvastatina Cálcica , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/imunologia , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/patologia , Sulfonamidas/administração & dosagem , Sulfonamidas/farmacologia , Sulfonamidas/uso terapêutico , Análise de Sobrevida , Síndrome de Resposta Inflamatória Sistêmica/etiologia , Síndrome de Resposta Inflamatória Sistêmica/imunologia , Síndrome de Resposta Inflamatória Sistêmica/metabolismoRESUMO
We studied the effect of intravascular activation of human neutrophils on the synthesis of cysteinyl leukotrienes (cysLT) and the formation of cerebral edema in guinea-pig brains. Challenge with the chemotactic formylated tripeptide fMLP (0.1 microM) of neutrophil-perfused brain in vitro resulted in blood-brain barrier disruption associated with a significant increase of cysLT. Both events were completely prevented by neutrophil pretreatment with a specific 5-lipoxygenase (5-LO) inhibitor. Perfusion with the 5-LO metabolite leukotriene B4 (10 nM), together with neutrophils treated with the 5-LO inhibitor, did not restore the alteration in permeability observed upon perfusion with untreated and activated neutrophils. The dual cysLT1-cysLT2 receptor antagonist BAYu9773 was more potent and more effective than a selective cysLT1 antagonist in preventing the brain permeability alteration induced by neutrophil activation. RT-PCR showed significant expression of cysLT2 receptor mRNA in human umbilical vein endothelial cells. Intravital microscopy in mice showed that inhibition of leukotriene synthesis significantly reduced firm adhesion of neutrophils to cerebral vessels without affecting rolling. These data support the hypothesis that neutrophil and endothelial cells cooperate toward the local synthesis of cysLT within the brain vasculature and, acting via the cysLT2 receptor on endothelial cells, may represent a contributing pathogenic mechanism in the development of cerebral inflammation and edema.
Assuntos
Edema Encefálico/fisiopatologia , Encefalite/fisiopatologia , Proteínas de Membrana/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Receptores de Leucotrienos/fisiologia , SRS-A/análogos & derivados , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacologia , Acetilcolina/farmacologia , Animais , Araquidonato 5-Lipoxigenase/metabolismo , Benzopiranos/farmacologia , Barreira Hematoencefálica/efeitos dos fármacos , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Edema Encefálico/metabolismo , Adesão Celular , Quimiotaxia de Leucócito/efeitos dos fármacos , Encefalite/metabolismo , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Cobaias , Humanos , Indóis/farmacologia , Leucotrieno A4/biossíntese , Leucotrieno B4/biossíntese , Leucotrieno B4/farmacologia , Inibidores de Lipoxigenase/farmacologia , Proteínas de Membrana/biossíntese , Camundongos , Microcirculação , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/enzimologia , Tamanho do Órgão/efeitos dos fármacos , Receptores de Leucotrienos/biossíntese , SRS-A/farmacologiaRESUMO
1 Myocardial ischemia/reperfusion is associated with inflammation, apoptosis and necrosis. During this process, c-jun N-terminal kinase is activated in cardiac myocytes resulting in apoptosis. 2 This study investigates the effects of AS601245, a nonpeptide ATP competitive JNK inhibitor, on infarct size caused by myocardial ischemia/reperfusion in anaesthetized rats. The left descending coronary artery of anaesthetized rats was occluded for 30 min and then reperfused for 3 h. AS601245 was administered 5 min before the end of the ischemia period as an i.v. bolus (1.5, 4.5 or 15 mg kg(-1) i.v.) followed by continuous i.v. infusion (18, 55 and 183 microg kg(-1) min(-1), respectively) during reperfusion. Controls received saline only. 3-Aminobenzamide, a poly(ADP-ribose) polymerase inhibitor, was used as reference compound at 10 mg kg(-1) i.v. bolus plus 0.17 mg kg(-1) min(-1) continuous infusion. 3 AS601245 significantly reduced infarct size at 4.5 mg kg(-1) (-44%; P<0.001) and 15 mg kg(-1) i.v. (-40.3%; P<0.001) similarly to 3-aminobenzamide (-44.2%; P<0.001). This protective effect was obtained without affecting hemodynamics or reducing ST-segment displacement. 4 The beneficial effects on infarct size correlated well with the reduction of c-jun phosphorylation (-85%; P<0.001 versus control) and of TUNEL-positive cells (-82.1%; P<0.001) in post-ischemic cardiomyocytes. No change in the phosphorylation state of p38 MAPK and ERK in post-ischemic heart was observed in the presence of AS601245 in comparison to the vehicle-treated group. 5 These results demonstrate that blocking the JNK pathway may represent a novel therapeutic approach for treating myocardial ischemia/reperfusion-induced cardiomyocyte death.
Assuntos
Acetonitrilas/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Infarto do Miocárdio/prevenção & controle , Miócitos Cardíacos/efeitos dos fármacos , Tiazóis/farmacologia , Anestesia , Animais , Benzotiazóis , Pressão Sanguínea/efeitos dos fármacos , Western Blotting , Doença das Coronárias/fisiopatologia , Fragmentação do DNA/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Masculino , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/complicações , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Fosforilação/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
We evaluated the capacity of anti-aggregating agents to influence thromboxane A(2) and prostacyclin formation, arachidonic acid-endoperoxide redirection, platelet aggregation and vessel tone, in isolated rabbit aorta incubated with homologous platelets. Picotamide (N,N'bis(3-pyridinylmethyl)-4-methoxy-isophthalamide), the only dual thromboxane A(2)-synthase inhibitor/receptor antagonist in clinical use, inhibited arachidonic acid-induced platelet aggregation with low potency, increased 180-fold by aorta presence. It inhibited thromboxane A(2) formation in platelets and, in aorta presence, increased prostacyclin formation. Ozagrel (OKY-046, (E)-3-(4-(1-imidazolylmethyl)phenyl)-2-propenoic acid), a pure thromboxane A(2)-synthase inhibitor, behaved similarly to picotamide, although the aorta caused a higher (600-fold) shift. The potency of the antagonist SQ 29,548 (1S-(1 alpha,2 beta(5Z),3 beta,4 alpha))-7-(3((2-((phenylamino)carbonyl)hydrazino)methyl)-7-oxabicyclo(2.2.1)hept-2-yl)-5-heptenoic acid) was unaffected by aorta. In coincubation experiments, arachidonic acid-challenge increased thromboxane A(2)-dependent vessel tone; picotamide increased prostacyclin and reduced thromboxane A(2) formation and vasoconstriction. Ozagrel mimicked picotamide; aspirin (acetylsalicylic acid) reduced aorta contractility, thromboxane A(2) and prostacyclin formation. SQ 29,548 reduced vasoconstriction without affecting eicosanoids. We demonstrate the importance of redirection of eicosanoids in the mechanism of action of thromboxane A(2) inhibitors/antagonists within platelet-vascular wall interactions. These findings bear relevance in the development of novel anti-thrombotic drugs.
Assuntos
Plaquetas/efeitos dos fármacos , Inibidores da Agregação Plaquetária/farmacologia , Receptores de Tromboxanos/antagonistas & inibidores , Tromboxano-A Sintase/antagonistas & inibidores , Animais , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/fisiologia , Ácido Araquidônico/farmacologia , Aspirina/farmacologia , Plaquetas/metabolismo , Plaquetas/fisiologia , Compostos Bicíclicos Heterocíclicos com Pontes , Comunicação Celular/efeitos dos fármacos , Dinoprosta/biossíntese , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiologia , Ácidos Graxos Insaturados , Hidrazinas/farmacologia , Técnicas In Vitro , Masculino , Metacrilatos/farmacologia , Tono Muscular/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , Ácidos Ftálicos/farmacologia , Ativação Plaquetária/efeitos dos fármacos , Coelhos , Tromboxano A2/biossínteseRESUMO
Spontaneously hypertensive stroke-prone rats (SHRSP) feature an established model for human cerebrovascular disease. SHRSP, kept on a high-salt permissive diet (JPD), develop hypertension, renal and brain damage. In this report we compared the behavior of female and male SHRSP regarding the main aspects of their pathological condition. Brain abnormalities, detected by magnetic resonance imaging, developed spontaneously in males after 42+/-3 days, in females after 114+/-14 days from the start of JPD. Survival was >3-fold longer for females than for males. The development of brain damage was preceded, in both genders, by an inflammatory condition characterized by the accumulation in serum and urine of acute-phase proteins. The increase in thiostatin level was significantly lower and delayed in female in comparison to male SHRSP. During JPD female and male SHRSP developed massive proteinuria, its worsening being significantly slower in females. The alterations of vasculature-bound barriers in kidney and brain were connected with endothelial dysfunction and relative deficiency in nitric oxide (NO). In thoracic aortic rings, basal release of NO was significantly higher in female than in male SHRSP, both if receiving and if not receiving JPD. The gender differences in SHRSP thus appear to be connected to a more efficient control in females of inflammation and of endothelial dysfunction.
Assuntos
Biomarcadores/análise , Encefalopatias/etiologia , Endotélio Vascular/metabolismo , Hipertensão/complicações , Inflamação/metabolismo , Proteínas de Fase Aguda/análise , Animais , Aorta/metabolismo , Proteínas Sanguíneas/análise , Encéfalo/irrigação sanguínea , Encefalopatias/patologia , Ensaio de Desvio de Mobilidade Eletroforética , Feminino , Hipertensão/mortalidade , Hipertensão/fisiopatologia , Rim/irrigação sanguínea , Cininogênios/análise , Imageamento por Ressonância Magnética , Masculino , Óxido Nítrico/metabolismo , Técnicas de Cultura de Órgãos , Proteinúria/etiologia , Ratos , Ratos Endogâmicos SHR , Fatores Sexuais , Fatores de TempoRESUMO
We present reference maps of the mouse serum proteome (run under reducing and non-reducing conditions), from control animals, from mice injected with lipopolysaccharide (LPS) to induce systemic inflammation, and from mice transgenic for human apolipoproteins A-I and A-II. Seventy-seven spots/spot chains from the reducing gels were identified by HPLC MS/MS, representing 28 distinct proteins, including a species-specific protease inhibitor, contrapsin, and high levels of carboxylesterase. The concentrations of acute-phase reactants were monitored for 96 h after LPS challenge. The greatest changes (four-fold 48 h after LPS administration) were observed for haptoglobin and hemopexin. Orosomucoid/alpha(1)-acid glycoprotein and apolipoprotein A-I increased steadily, to 50-60% above baseline at 96 h from stimulation. In mice transgenic for human apolipoprotein A-I the levels of expression of orosomucoid/alpha(1)-acid glycoprotein, alpha(1)-macroglobulin, esterase, kininogen and contrapsin were altered compared to knockout mice lacking apolipoprotein A-I. In contrast, except for the presence of apolipoprotein A-II, no statistically significant difference was observed in mice transgenic for human apolipoprotein A-II.