The Experts below are selected from a list of 23403 Experts worldwide ranked by ideXlab platform
Steven H. Abman - One of the best experts on this subject based on the ideXlab platform.
-
Developmental Physiology of the Pulmonary Circulation
The Lung, 2014Co-Authors: Reuben B. Dodson, Csaba Galambos, Steven H. AbmanAbstract:Abstract Normal development of the Pulmonary Circulation requires precise coordination of vascular growth, structure, and function, at the cellular, tissue, and organ levels. Progressive vascular maturation during early development is essential for a smooth transition to postnatal life. The unique characteristics of the fetal and transitional Pulmonary Circulation and the abnormalities in this system that contribute to neonatal lung disease are complex and involve diverse signaling pathways. Systematic in vivo and in vitro studies with human tissues and specific animal models of normal developmental physiology, and the abnormal development, may provide helpful insights into new clinical strategies for more successful treatment of neonatal Pulmonary vascular disease. This chapter summarizes the current knowledge on maturation in Pulmonary vascular growth, structure, and function, and briefly reviews mechanisms that are critical for understanding the pathogenesis and pathobiology of neonatal lung diseases.
-
The Normal Fetal and Neonatal Pulmonary Circulation
Textbook of Pulmonary Vascular Disease, 2010Co-Authors: Steven H. Abman, Robin H. SteinhornAbstract:In utero, the Pulmonary Circulation is characterized by high Pulmonary vascular resistance (PVR) and low Pulmonary blood flow, as the fetal lung receives less than 8% of combined ventricular output. At birth, the Pulmonary Circulation must suddenly undergo a striking vasodilation to allow for an eightfold to tenfold rise in blood flow for the lung to assume its postnatal role in gas exchange. This acute change in Pulmonary vascular tone and reactivity is followed by progressive vascular growth, remodeling, and structural adaptations, as the lung Circulation continues to grow and mature over time in response to postnatal stimuli. Normal lung vascular development is not only critical for successful adaptation at birth, but ongoing growth and remodeling remains essential throughout postnatal life. The ability of the lung to successfully achieve normal gas exchange requires the growth and maintenance of an intricate system of airways and vessels, including the establishment of a thin yet vast blood–gas interface. Insights into basic mechanisms that regulate lung growth and maturation continue to provide new understanding of lung diseases and their treatment, in newborns and adults alike. Vascular growth in the lung is not only important regarding the risk for Pulmonary hypertension, but normal vascular growth and structure are absolutely necessary for establishing sufficient surface area for gas exchange. Developmental abnormalities of the Pulmonary Circulation contribute to the pathological and pathophysiological processes of diverse diseases, including persistent Pulmonary hypertension of the newborn, lung hypoplasia, congenital diaphragmatic hernia, and congenital heart disease. This chapter provides a brief overview of structural and functional changes in the Pulmonary Circulation that contribute to PVR during fetal life and mechanisms that contribute to the dramatic changes in vascular tone at birth in the normal newborn.
-
Fasudil inhibits the myogenic response in the fetal Pulmonary Circulation
American journal of physiology. Heart and circulatory physiology, 2008Co-Authors: Pierre Tourneux, Marc A Chester, Theresa R. Grover, Steven H. AbmanAbstract:In addition to high Pulmonary vascular resistance (PVR) and low Pulmonary blood flow, the fetal Pulmonary Circulation is characterized by mechanisms that oppose vasodilation. Past work suggests tha...
-
Chapter 7 – Developmental Physiology of the Pulmonary Circulation
The Lung, 2004Co-Authors: Steven H. AbmanAbstract:Publisher Summary This chapter reviews the physiologic regulation of the developing Pulmonary Circulation, including mechanisms that regulate vascular tone and reactivity in the fetal lung; mechanisms that contribute to adaptive changes at birth and the early postnatal period; and mechanisms that may contribute to the failure of Pulmonary vascular resistance (PVR) to fall in neonates with severe Pulmonary hypertension. Postnatal survival depends upon the ability of the Pulmonary Circulation to undergo rapid and dramatic vasodilation during the first minutes after birth. Normal development of the lung Circulation is determined by the precise coordination of numerous signals from multiple cell types, which include diverse transcription factors, growth factors, chemokines, cytokines, vasoactive products, matrix proteins and others. Physiologically, the fetal Pulmonary Circulation is characterized by the presence of high vascular resistance, and the ability to oppose vasodilation and maintain low blood flow in utero. The ability to respond to vasoactive stimuli increases with maturation. The NO-cGMP cascade plays an important role in the regulation of vascular tone and reactivity of the fetal and transitional Pulmonary Circulation, and abnormalities in this system contribute to abnormal Pulmonary vascular tone and reactivity in an experimental model of persistent Pulmonary hypertension of the newborn (PPHN).
-
The Pulmonary Circulation in bronchoPulmonary dysplasia
Seminars in neonatology : SN, 2003Co-Authors: Thomas A. Parker, Steven H. AbmanAbstract:Abnormalities of the Pulmonary Circulation are increasingly being recognized as a major contributor to the high morbidity and mortality of bronchoPulmonary dysplasia. Historically, studies have focused on the importance of Pulmonary hypertension to the pathophysiology of BPD, with the assumption that Pulmonary vascular abnormalities are a secondary consequence of primary injury to the airspace. Recent studies suggest, however, that abnormalities of the Pulmonary vasculature, including altered growth and structure, may directly contribute to the abnormal alveolarization that characterizes the condition. In this article, we briefly outline mechanisms of Pulmonary vascular injury in infants at risk of BPD. We then focus on the recognition and management of Pulmonary hypertension in these infants. Finally, we review how disordered Pulmonary vascular growth may contribute to the pathogenesis of BPD and emphasize the importance of the reciprocal development of the airspace and the Pulmonary Circulation.
Yuansheng Gao - One of the best experts on this subject based on the ideXlab platform.
-
Regulation of the Pulmonary Circulation in the Fetus and Newborn
Physiological reviews, 2010Co-Authors: Yuansheng Gao, J. Usha RajAbstract:During the development of the Pulmonary vasculature in the fetus, many structural and functional changes occur to prepare the lung for the transition to air breathing. The development of the Pulmonary Circulation is genetically controlled by an array of mitogenic factors in a temporo-spatial order. With advancing gestation, Pulmonary vessels acquire increased vasoreactivity. The fetal Pulmonary vasculature is exposed to a low oxygen tension environment that promotes high intrinsic myogenic tone and high vasocontractility. At birth, a dramatic reduction in Pulmonary arterial pressure and resistance occurs with an increase in oxygen tension and blood flow. The striking hemodynamic differences in the Pulmonary Circulation of the fetus and newborn are regulated by various factors and vasoactive agents. Among them, nitric oxide, endothelin-1, and prostaglandin I(2) are mainly derived from endothelial cells and exert their effects via cGMP, cAMP, and Rho kinase signaling pathways. Alterations in these signaling pathways may lead to vascular remodeling, high vasocontractility, and persistent Pulmonary hypertension of the newborn.
-
role of veins in regulation of Pulmonary Circulation
American Journal of Physiology-lung Cellular and Molecular Physiology, 2005Co-Authors: Yuansheng Gao, Usha J RajAbstract: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 review, the role of veins in regulation of the Pulmonary Circulation, particularly during the perinatal period and under certain pathophysiological conditions, is discussed. In the fetus, Pulmonary veins contribute a significant fraction to total Pulmonary vascular resistance. At birth, the veins as well as the arteries relax in response to endothelium-derived nitric oxide and dilator prostaglandins, thereby assisting in the fall in Pulmonary vascular resistance. These effects are oxygen dependent and modulated by cGMP-dependent protein kinase. Under chronic hypoxic conditions, Pulmonary veins undergo remodeling and demonstrate substantial constriction and hypertrophy. In a number of species, including the human, Pulmonary veins are also the primary sites of action of certain vasoconstrictors such as endothelin and thromboxane. In various pathological conditions, there is an increased synthesis of these vasoactive agents that may lead to Pulmonary venous constriction, increased microvascular pressures for fluid filtration, and formation of Pulmonary edema. In conclusion, the significant role of veins in regulation of the Pulmonary Circulation needs to be appreciated to better prevent, diagnose, and treat lung disease.
Usha J Raj - One of the best experts on this subject based on the ideXlab platform.
-
role of veins in regulation of Pulmonary Circulation
American Journal of Physiology-lung Cellular and Molecular Physiology, 2005Co-Authors: Yuansheng Gao, Usha J RajAbstract: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 review, the role of veins in regulation of the Pulmonary Circulation, particularly during the perinatal period and under certain pathophysiological conditions, is discussed. In the fetus, Pulmonary veins contribute a significant fraction to total Pulmonary vascular resistance. At birth, the veins as well as the arteries relax in response to endothelium-derived nitric oxide and dilator prostaglandins, thereby assisting in the fall in Pulmonary vascular resistance. These effects are oxygen dependent and modulated by cGMP-dependent protein kinase. Under chronic hypoxic conditions, Pulmonary veins undergo remodeling and demonstrate substantial constriction and hypertrophy. In a number of species, including the human, Pulmonary veins are also the primary sites of action of certain vasoconstrictors such as endothelin and thromboxane. In various pathological conditions, there is an increased synthesis of these vasoactive agents that may lead to Pulmonary venous constriction, increased microvascular pressures for fluid filtration, and formation of Pulmonary edema. In conclusion, the significant role of veins in regulation of the Pulmonary Circulation needs to be appreciated to better prevent, diagnose, and treat lung disease.
Sergio Moral - One of the best experts on this subject based on the ideXlab platform.
-
Imaging Techniques and the Evaluation of the Right Heart and the Pulmonary Circulation
Revista espanola de cardiologia, 2010Co-Authors: Javier Sanz, Leticia Fernández-friera, Sergio MoralAbstract:Since the right side of the heart and the Pulmonary Circulation are regarded as secondary components of the circulatory system, their role in disease has traditionally not received the same attention as their counterparts in the systemic Circulation. This was partly because precise noninvasive study of these structures was difficult. For many years, chest radiography and invasive angiography were the only techniques available for imaging the minor Circulation. The development of transthoracic echocardiography and nuclear techniques has produced a significant leap forward for noninvasive imaging, particularly of the right ventricle. More recently, novel echocardiographic techniques, and advances in computed tomography and magnetic resonance imaging, in particular, have expanded our diagnostic armamentarium and provided new insights into the anatomy and function of the Pulmonary Circulation in both health and disease. This article contains a review of the current status of techniques for imaging the right side of the heart and the Pulmonary Circulation.
J. Usha Raj - One of the best experts on this subject based on the ideXlab platform.
-
Regulation of the Pulmonary Circulation in the Fetus and Newborn
Physiological reviews, 2010Co-Authors: Yuansheng Gao, J. Usha RajAbstract:During the development of the Pulmonary vasculature in the fetus, many structural and functional changes occur to prepare the lung for the transition to air breathing. The development of the Pulmonary Circulation is genetically controlled by an array of mitogenic factors in a temporo-spatial order. With advancing gestation, Pulmonary vessels acquire increased vasoreactivity. The fetal Pulmonary vasculature is exposed to a low oxygen tension environment that promotes high intrinsic myogenic tone and high vasocontractility. At birth, a dramatic reduction in Pulmonary arterial pressure and resistance occurs with an increase in oxygen tension and blood flow. The striking hemodynamic differences in the Pulmonary Circulation of the fetus and newborn are regulated by various factors and vasoactive agents. Among them, nitric oxide, endothelin-1, and prostaglandin I(2) are mainly derived from endothelial cells and exert their effects via cGMP, cAMP, and Rho kinase signaling pathways. Alterations in these signaling pathways may lead to vascular remodeling, high vasocontractility, and persistent Pulmonary hypertension of the newborn.
