The article presents a study which investigates the endothelium-independent vasorelaxation by the selective estrogen receptor alpha (ERΑ) agonist propyl pyrazole triol (PPT) in the aortic smooth muscle of rats. The study involves several compounds,such as the protein kinase G (PKG) and potassium channel inhibitors, which were tested against PPT-dependent aortic relaxation. Results show that the endothelial removal has no effect on PPT vasorelaxation.