The CDOCKER program was subsequently used for the docking

t modify KCl response. The contraction induced by phenylephrine was greater in aortic segments from SHR when compared with Wistar rats; however, after anti-TLR4 antibody treatment of SHRs the phenylephrine-induced responses were lower. Furthermore, endothelium-dependent relaxation to acetylcholine was lower in SHRs, being these responses increased by the anti-TLR4 antibody treatment. To evaluate the influence of endothelium in the response to phenylephrine, this layer was mechanically removed. In these conditions, the response to phenylephrine was increased in the three groups; however, this increase was smaller in SHRs, as shown by the analysis of dAUC values, while the antiTLR4 antibody treatment restored this increase. These results suggest that hypertension reduces the endothelial modulation of phenylephrine responses and that the treatment reestablishes this modulation. The tension developed by the NO synthase antagonist L-NAME after phenylephrine contraction was lower in SHRs when compared with Wistar rats, and this contraction was increased after treatment of SHRs with the antiTLR4 antibody. PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19658058 These results indirectly suggest that treatment significantly increases NO production. Altogether, these results allow us to propose that the anti-TLR4 antibody treatment improves endothelial dysfunction in SHRs, and this improvement most likely occurs by increasing NO bioavailability. Results Angiotensin II contributes to increased vascular TLR4 gene expression in SHRs TLR4 mRNA expression was greater in aortic segments from SHRs when compared with those from Wistar rats; this greater expression was reduced after treatment of SHRs with the AT1 receptor antagonist losartan, which suggests that Ang II contributes to this increased expression. MedChemExpress TG-02 Similarly, TLR4 mRNA levels were greater in VSMCs from SHRs than from Wistar rats. Immunofluorescence experiments confirm the greater expression of TLR4 in aorta from SHR when compared with Wistar rats; this receptor was localized in the three layers of the vascular wall. TLR4 inhibition decreases the contribution of oxidative stress to the vasoconstrictor and vasodilator responses in aortas from hypertensive rats Endothelial dysfunction accompanying hypertension is frequently associated with reduction in NO bioavailability caused by increased ROS production, among other mechanisms. Therefore, we analyzed the effect of anti-TLR4 antibody treatment on the contribution of ROS to vascular function. The superoxide anion scavenger tiron, the NADH oxidase inhibitor apocynin and the hydrogen peroxide detoxificant catalase did not affect phenylephrine-induced contraction in Wistar rats, while the three drugs reduced those responses in SHRs. Treatment with the anti-TLR4 antibody completely abolished the inhibitory effect of the three antioxidants analyzed. On the other hand, tiron, apocynin and catalase did not affect acetylcholine-induced relaxation in Wistar rats but increased that response in SHRs; after anti-TLR4 antibody treatment of SHRs the enhancing effect of the three compounds was abolished. Altogether, these results suggest that TLR4 increased oxidative stress and this would contribute to the impaired vascular function observed in aortas from hypertensive rats. In an attempt to investigate if these effects of TLR4 are related to the TLR4 inhibition reduces blood pressure and heart rate in hypertensive rats At the end of the treatment, body weight and the tibia length was similar in the three animal grou