Because hypoxic pulmonary vasoconstriction occurs mainly in the small pulmonary arteries, the authors investigated the effects of drugs acting on the nitric oxide (NO) pathway and the calcium and potassium channels in the peripheral pulmonary circulation, without interference with the overall pulmonary or systemic circulation. Mixed venous blood was infused in wedged areas to study the pressure...

Adverse events in utero are associated with the occurrence of chronic diseases in adulthood. We previously demonstrated in mice that perinatal hypoxia resulted in altered pulmonary circulation in adulthood, with a decreased endothelium-dependent relaxation of pulmonary arteries, associated with long-term alterations in the nitric oxide (NO)/cyclic GMP pathway. The present study investigated whe...

I AHPR = acute hypoxic pressor response T he pulmonary circulation responds to acute hypoxia with increases in pulmonary artery pressure and vascular resistance. This acute hypoxic pressor response (AHPR) is a unique physiologic feature distinguishing the pulmonary from the systemic circulation which dilates in response to hypoxia.’ Since Von Euler and Liljestrand described the phenomenon of ac...

• The regulation of the pulmonary circulation is inextricably linked to the role of the lungs in gas exchange. Accordingly, it is not surprising that hypoxia and acidosis predominate as stimuli for vasomotor activity or that their main effects are exerted locally on the pulmonary vascular tree. Although pulmonary vasomotor nerves do exist, they operate more to adjust the distensibility of capac...

Gao, Yuansheng, and J. Usha Raj. Role of veins in regulation of pulmonary circulation. Am J Physiol Lung Cell Mol Physiol 288: L213–L226, 2005; doi: 10.1152/ajplung.00103.2004.—Pulmonary veins have been seen primarily as conduit vessels; however, over the past two decades, a large amount of evidence has accumulated to indicate that pulmonary veins can exhibit substantial vasoactivity. In this r...

REFERENCES 1 Task Force for Diagnosis and Treatment of Pulmonary Hypertension of European Society of Cardiology (ESC), European Respiratory Society (ERS), International Society of Heart and Lung Transplantation (ISHLT), et al. Guidelines for the diagnosis and treatment of pulmonary hypertension. Eur Respir J 2009; 34: 1219–1263. 2 Newman JH, Phillips JA, Lloyd JE. Narrative review: the enigma o...

Utilizing the 1311-MAA (macroaggregated albumin labeled with iodine-131) scintillation scanning method, regional pulmonary blood flow distribution was studied in 47 cardiac patients with pulmonary hypertension. Remarkable increase of blood flow in the upper zones of the lung together with decrease in the lower zones was found in the majority of the patients with mitral valve disease, while in t...