Substrate utilization in the perinatal lung.

Abstract

Lung cellular metabolism is fundamental to both respiratory and nonrespiratory function. The lung has very little energy reserve and is highly dependent on circulating substrates. The pattern of substrate utilization is determined primarily substrate availability, competition between certain substrates, and the ability of lung cells for uptake and metabolism. The lung uses a number of substrates (glucose, lactate, fatty acids, choline, ketone bodies, and amino acids) as basic building blocks for synthesis, as energy-providing fuels, to provide NADPH for lipid biosynthesis, and for glutathione production. Since the availability of substrates, the cellular profile, the hormonal environment, and the physiological state of the lung are drastically altered during perinatal lung development, this review focuses on current knowledge of lung substrate utilization during this critical period. Because development of the surfactant system has been specifically linked to infant respiratory distress syndrome, the majority of investigations relate to substrate utilization for phospholipid synthesis. It is hoped that this review will outline basic principles for interpretation of information on perinatal substrate utilization, collate available data, and provide a stimulus for future research.