Altered Metabolic Function of the Pulmonary Microcirculation: Early Detection of Lung Injury and Possible Functional Significance

A profile of amino acid and catecholamine levels during endotoxin-induced acute lung injury in sheep: searching for potential markers of the acute respiratory distress syndrome

The identification of plasma markers of the course of the acute respiratory distress syndrome (ARDS) is needed to improve its treatment and to further advance the development of new therapeutic agents. The status of markers of lung injury in ARDS is reviewed and some new potential markers are proposed. This study focused on plasma amino acids, related amino compounds, and catecholamine levels during the acute phase of endotoxin-induced lung injury in 8 sheep characterized by the onset of pulmonary edema caused by increased microvascular permeability. A number of significant changes from baseline values were found. During the sixth hour of a 12-hour period of endotoxin infusion, norepinephrine, epinephrine, and alanine levels increased whereas the isoleucine level decreased. During the sixth hour of the immediate postendotoxin period, the taurine level increased while the levels of arginine, citrulline, glycine, isoleucine, methionine, ornithine, serine, threonine, and tryptophan decreased. These findings are compared with prior studies in human subjects detailing the amino acid profile characteristic of advanced sepsis. We conclude that the present profile of catecholamine and amino acid changes during endotoxemia in sheep deserves further study in human subjects to determine its significance as a marker of the early stage of ARDS.

The adult respiratory distress syndrome: a review

The adult respiratory distress syndrome, characterized by hypoxemia, reduced pulmonary expansion, and noncardiogenic pulmonary edema, is a clinical entity with a high mortality rate that has been recognized only relatively recently. We present the newest aspects of the subject.