Related Experiment Video
Updated: Mar 12, 2026

Analytical Techniques for Assaying Nitric Oxide Bioactivity
Published on: June 18, 2012
Hypotensive effect and vascular relaxation in different arteries induced by the nitric oxide donor RuBPY
Amanda de Carvalho Pereira1, Alice Valença Araújo2, Michele Paulo1
1Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
Abstract:
NO donors are compounds that release NO that can be used when the endogenous NO bioavailability is impaired. The compound cis-[Ru(bpy)2(py)(NO2)](PF6) (RuBPY) is a nitrite-ruthenium, since it has a NO2 in its molecule. The aim of the present study was to evaluate the effect of RuBPY on arterial pressure, as well as on the vascular relaxation of different vascular arteries in renal hypertensive (2K-1C) and normotensive (2K) rats. We have evaluated the arterial pressure and heart rate changes as well as the RuBPY and SNP-induced relaxation (thoracic aorta, mesenteric resistance, coronary and basilar arteries). The administration of RuBPY in awake rats evoked a smaller but long lasting hypotensive effect when compared to SNP, with no increase in heart rate. The relaxation induced by RuBPY was similar between 2K-1C and 2K rats in thoracic aorta, mesenteric resistance and coronary arteries. However, the relaxation induced by RuBPY was smaller in basilar arteries from 2K-1C than in 2K. Taken together, our results show that RuBPY presents several advantages over SNP, since it does not induce hypotensive effect in normotensive animals, the hypotensive effect is slower, with no reflex tachycardia, and it is long lasting. In addition, RuBPY induces coronary artery relaxation (useful for angina) and presented only a small effect on basilar artery (may not induce headache).
Related Concept Videos
Antihypertensive Drugs: Vasodilators
Nitric Oxide Signaling Pathway
Antianginal Drugs: Nitrates and β-Blockers
Organic nitrates, such as nitroglycerin, play a pivotal role. Once metabolized, they liberate nitric oxide, a molecular marvel. Nitric oxide triggers guanylyl cyclase and augments cGMP production. This biochemical cascade orchestrates the relaxation of vascular smooth muscles, ushering in vasodilation and enhancing coronary blood flow....
Treatment for Pulmonary Arterial Hypertension: Phosphodiesterase Inhibitors
Among the PDE5 inhibitors, sildenafil (Revatio) stands out as a competitive and selective inhibitor. It operates by elevating cellular levels of cGMP and augmenting signaling through the cGMP-PKG pathway, promoting vasodilation. Upon oral...
Treatment for Pulmonary Arterial Hypertension: Prostacyclin Receptor Agonists
These agonists bind to the IPR receptor situated on the plasma membrane of the pulmonary artery smooth muscle cells. This binding triggers a cascade of reactions known as the GS-AC-cAMP-PKA pathway. This pathway results in the relaxation of smooth muscle...
Autoregulation of Blood Flow
Chemical Signaling in Autoregulation
Chemical signaling operates at the precapillary sphincter level, inciting either contraction or relaxation....

