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in close agreement with previously published that demonstrated the efficacy of NO inhibitors BIX01294 or endothelial elimination in preventing low dose although not large dose nitroglycerin induced vasodilation. Not surprisingly, obvious ramifications of GTN in decreasing diastolic blood pressure in rats were markedly reduced when the animals were pre-treated with wortmannin or Akt inhibitor. Taken together, these represent compelling evidence implicating signal transduction pathways in the mediation of GTNs pharmacological effects by causing eNOS. Indeed, studies done with endothelial cells and shown in Fig. 4 demonstrated that 0. 5 uM GTN promptly induced the phosphorylation of eNOS in the site Ser 1177, which was completely inhibited by both PI3K or Akt inhibitor. These reports were recapitulated in human endothelial microvascular cells. In both BAEC and HMEC, eNOS phosphorylation was temporally paralleled by Akt activation, suggesting the involvement of the pathway in GTN induced activation. Apparently, we also found that PTEN, the enzyme that opposes PI3K activity by degrading InsP3, Plastid was rapidly inhibited by GTN. PTEN inhibition was determined through the Western blot analysis of the inhibitory site Ser 380 phosphorylation and through the quantification of the energetic second messenger InsP3. PTEN inhibition was more confirmed by the measurement of PTEN task after immunopurification from lysates of cells previously exposed to GTN. Notably, PTEN lipid phosphatase activity is dependent on the critical active deposit Cys 124. In its reduced form the lower pKa Cys 124 thiolate catalyzes the elimination of the 3 phosphate group of phosphatidylinositol in similarity to the proposed and widely-accepted system of ALDH 2 inhibition by GTN. However, distinctive from ALDH 2, which is confined in mitochondria, PTEN, which is itself fairly painful and sensitive to inhibition by oxidants and by Daclatasvir electrophiles, exists mainly in the cytosol, especially at the vicinity of the plasma membrane, and is thus prone to communicate with diffusible xenobiotics upon their entry in to the cell. Certainly, the fundamental part of ALDH 2 in GTN bio-conversion to NO was claimed largely on the idea of knockout reports that showed that ALDH 2 knockout animals are less attentive to low-dose GTN than ALDH 2 competent animals. Nonetheless, exhaustion of ALDH 2 has been related to increased oxidative stress and vascular dysfunction probably due to increased degrees of reactive species production. Ergo, with the currently available data it's impossible to tell apart whether the GTN tolerant phenotype exhibited by the ALDH 2 knockout animal is a consequence of its failure to transform GTN to NO or, as an alternative, is attributable to dysregulation of oxidant vulnerable signal transduction pathways including the PI3K/Akt/PTEN axis.