Navegando por Palavras-chave "Phosphodiesterase"

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    Altered reactivity of gastric fundus smooth muscle in the mouse with targeted disruption of the kinin B(1) receptor gene
    (Elsevier B.V., 2009-05-01) Barbosa, Ana M. R. B. [UNIFESP]; Felipe, Sandra A. [UNIFESP]; Araujo, Ronaldo C. [UNIFESP]; Kawamoto, Elisa M.; Carvalho, Maria H. C.; Scavone, Cristoforo; Pesquero, Joao B. [UNIFESP]; Shimuta, Suma I. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)
    Relaxing action of sodium nitroprusside (SNP) was significantly reduced in the stomach fundus of mice lacking the kinin B(1) receptor (B(1)(-/-)). Increased basal cGMP accumulation was correlated with attenuated SNP induced dose-dependent relaxation in B(1)(-/-) when compared with wild type (WT) control mice. These responses to SNP were completely blocked by the guanylate cyclase inhibitor ODQ(10 mu M). It was also found that Ca(2+)-dependent, constitutive nitric oxide synthase (cNOS) activity was unchanged but the Ca(2+)-independent inducible NOS (iNOS) activity was greater in B(1)(-/-) mice than in WT animals. Zaprinast (100 mu M), a specific phosphodiesterase inhibitor, increased the nitrergic relaxations and the accumulation of the basal as well as the SNP-stimulated cGMP in WT but not in B(1)(-/-) stomach fundus. From these findings it is concluded that the inhibited phosphodiesterase activity and high level of cGMP reduced the resting muscle tone, impairing the relaxant responses of the stomach in B(1)(-/-) mice. in addition, it can be suggested that functional B(2) receptor might be involved in the NO compensatory mechanism associated with the deficiency of kinin B(1) receptor in the gastric tissue of the transgenic mice. (C) 2009 Elsevier Inc. All rights reserved.
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    Sildenafil citrate protects skeletal muscle of ischemia-reperfusion injury: immunohistochemical study in rat model
    (Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia, 2013-04-01) Armstrong, Dinani Matoso Fialho de Oliveira; Armstrong, Anderson da Costa; Figueiredo, Regina Célia Bressan Queiroz; Florentino, Joao Eduardo; Saad, Paulo Fernandes [UNIFESP]; Fox-Talbot, Karen; Halushka, Marc Kenneth; Berkowitz, Dan E.; Taha, Murched Omar [UNIFESP]; Fagundes, Djalma José [UNIFESP]; Sao Francisco Valley Federal University Department of Surgery; UNIVASF Department of Cardiology; Research Center Aggeu Magalhaes Department of Microbiology; Pernambuco Federal University; UNIVASF Department of Surgery; Johns Hopkins University Department of Pathology; Johns Hopkins University Department of Anesthesiology and Critical Care Medicine; Universidade Federal de São Paulo (UNIFESP)
    PURPOSE: To investigate the effect of sildenafil citrate (SC) on skeletal muscle ischemia-reperfusion (IR) injury in rats. METHODS: Adult male Wistar rats were randomized into three groups: vehicle-treated control (CTG), sildenafil citrate-treated (SCG), and sham group (SG). CTG and SCG had femoral artery occluded for 6 hours. Saline or 1 mg/kg of SC was given 5.5 hours after occlusion. SG had a similar procedure without artery occlusion. Soleus muscle samples were acquired 4 or 24h after the reperfusion. Immunohistochemistry caspase-3 analysis was used to estimate apoptosis using the apoptotic ratio (computed as positive/negative cells). Wilcoxon rank-sum or Kruskal-Wallis tests were used to assess differences among groups. RESULTS: Eighteen animals were included in the 4h reperfusion groups and 21 animals in the 24h reperfusion groups. The mean apoptotic ratio was 0.18±0.1 for the total cohort; 0.14±0.06 for the 4h reperfusion groups and 0.19±0.08 for the 24h groups (p<0.05). The SCG had lower caspase-3 ratio compared to the control groups at the 24h reperfusion time point (p<0.05). CONCLUSION: Sildenafil citrate administration after the onset of the ischemic injury reduces IR-induced cellular damage in skeletal muscle in this rat hindlimb ischemia model.