Hypoxic pulmonary hypertension: the paradigm is changing

We began in the early 2000s to explore the hypothesis that vasoconstrictor mechanisms, selectively altered in the lung, were significant contributors to the increase in pulmonary vascular resistance in pulmonary hypertension. We found that in the normal rat pulmonary circulation the RhoA-ROCK pathway is a greater contributor to vasoconstriction than it is in systemic vessels, demonstrating an important phenotypic difference in the regulation of vascular tone in the two circulations.