During fetal life, gas exchange is carried out in the placenta. The lung does not have a physiological role, apart from possible metabolic functions which include secretion of hormones, enzymatic conversion of inactive substances to functional hormones, and degradation of active materials to inactive metabolites. Blood flow through the lungs is quite low during fetal life; most of the systemic ...

The pulmonary circulation, at the unique crossroads between the left and the right heart, is submitted to large physiologic hemodynamic variations and possesses numerous important metabolic functions mediated through its vast endothelial surface. There are many pathologic conditions that can directly or indirectly affect the pulmonary vasculature and modify its physiology and functions. Pulmona...

DIABETES IS AN EPIDEMIC in the United States, affecting 8% of the population. The hallmark of diabetes is hyperglycemia due to either insulin deficiency or insulin resistance. Systemic vascular dysfunction is a central part of the pathophysiology of both type I insulin-dependent and type II non-insulin-dependent diabetes and involves both the microand macrocirculation (11). Coronary heart disea...

The pyrrolizidine alkaloid, fulvine, is now accepted as a major cause of veno-occlusive disease of the liver in the West Indies, where it is ingested as a decoction of the plant Crotalaria fulva in bush tea. Fulvine is similar in chemical structure to monocrotaline, which is known to cause pulmonary hypertension in rats. Thirty young female rats were given a single dose of fulvine either by int...

We were sitting, I recall, in the canteen of the Medical School at Birmingham. It must have been 1958. I had just returned from a year and a half at the Bellevue Hospital, New York, my mind still reeling from the experience of working in the cardiopulmonary laboratory of Andre Cournand. Donald Heath had returned from the Mayo Clinic where he had coolly reshaped the face of pulmonary vascular pa...

Factors regulating pressure and flow in the lungs are reviewed with particular emphasis on their role in regulating blood flow velocity and distribution within the lung capillaries. The behaviour of the pulmonary arterial, system, alveolar capillaries, and pulmonary venous system are considered individually. The effect of heart disease on lung capillary blood flow is examined.

The first description of the effects of hypoxia on the pulmonary circulation was made by Bradford and Dean in the UK exactly 100 years ago.' However, scientific interest in this field only began with the discovery of hypoxic pulmonary vasoconstriction in the cat by von Euler and Liljestrand2 in 1946, and in man a year later in Andre Coumand's laboratory.3 Despite extensive research in this fiel...

Aminorex (2-amino-5-phenyl-2-oxazoline) is an appetite-suppressing drug which was available in Switzerland from November 1965 to October 1968. In 1967 a sudden 20-fold increase in the incidence of primary pulmonary hypertension was observed in a Swiss medical clinic. It was noticed that a considerable number of these patients had taken aminorex to reduce weight. A similar increase in the incide...

The question of whether or not the blood-vessels of the pulmonary circulation are under the control of the central nervous system has been a subject for difference of opinion for many years. Several years ago I published ( I ) the results of some experiments bearing upon this problem, which led me to a belief in the existence of a vasomotor supply to the lesser circulation. Since then I have ca...

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 we...