Related Experiment Video
Updated: Jun 23, 2026

Increasing Pulmonary Artery Pulsatile Flow Improves Hypoxic Pulmonary Hypertension in Piglets
Published on: May 11, 2015
Primary pulmonary hypertension treated with oral phentolamine
Abstract:
A patient with symptomatic primary pulmonary artery hypertension underwent therapeutic trials with parenteral and oral phentolamine. Before drug therapy, he manifested marked increases in pulmonary artery pressure and pulmonary arteriolar resistance during exercise. This hypertensive response to exercise was significantly attenuated by parenteral phentolamine. He also manifested sustained hemodynamic improvement with the same degree of attenuation of exercise-induced increases in pulmonary artery pressure and pulmonary arteriolar resistance 7 months after initiation of therapy with oral phentolamine. Twenty months after initiation of therapy, the patient continues to enjoy symptomatic improvement with a marked increase in exercise tolerance.
Related Concept Videos
Pulmonary Hypertension: Classification and Pathogenesis
There are various classifications for PH, each relating to different underlying causes and also...
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: Endothelin Receptor Antagonists
ETs are synthesized through a complex sequence of enzymatic steps, primarily involving an enzyme referred to as endothelin-converting enzyme (ECE). Of...
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...
Treatment for Pulmonary Arterial Hypertension: Receptor Tyrosine Kinase Inhibitors and Calcium Channel Blockers
TKIs, such as imatinib (Gleevec), are particularly effective in tackling the growth and mitogenic factors that become upregulated in PAH patients. These factors contribute to the...
Treatment for Pulmonary Arterial Hypertension: Oxygen Therapy for Respiratory Failure
Oxygen therapy is vital in increasing and maintaining blood oxygen levels in PAH patients. As a result, it aids in reducing fatigue, improving...

