linoleic-acid and Respiratory-Distress-Syndrome

Oxygen free radicals are important mediators of both physiological and pathological events. In acute lung injury, the activated lymphocytes stimulate tumor necrosis factor (TNF) and other cytokines. These lymphokines augment free radical generation by polymorphonuclear leukocytes (PMNLs), macrophages and other cells which may ultimately produce acute respiratory distress syndrome (ARDS). This is supported by our results presented here in that there is a significant increase in lipid peroxidation products in patients with established ARDS. The amount of lipid peroxidation was significantly higher in the established ARDS group compared to patients who are at risk for ARDS. Nitric oxide concentrations were significantly decreased in established ARDS compared to the control and those who are at risk for ARDS. Fatty acid analysis of the plasma phospholipid fraction revealed a significant decreased in linoleic acid, gamma-linolenic acid, dihomo-gamma-linolenic acid and arachidonic acid levels of n-6 series and alpha-linolenic acid, eicosapentaenoic acid, docosa-hexanenoic acid of n-3 series. Patients who are at risk for ARDS have decreased levels of gamma-linolenic acid of the n-6 series, alpha-linolenic acid and eicosapentaenoic acid of the n-3 series. These results suggest that lipid peroxides and alteration in essential fatty acid metabolism may have a role in the pathogenesis of ARDS.

Topics: alpha-Linolenic Acid; Arachidonic Acid; Docosahexaenoic Acids; Eicosapentaenoic Acid; Fatty Acids, Essential; gamma-Linolenic Acid; Humans; Linoleic Acid; Lipid Peroxidation; Malondialdehyde; Nitric Oxide; Nitrites; Oleic Acid; Oxidative Stress; Respiratory Distress Syndrome; Risk Factors; Thiobarbituric Acid Reactive Substances

Gas chromatograph-mass spectrometry has been applied to the analysis of plasma linoleic acid and one of its oxidation products, 4-hydroxy-2-nonenal (HNE), in adult patients with the acute respiratory distress syndrome (ARDS). Peak areas of total ion chromatograms showed there to be negative correlations between loss of linoleic acid and formation of HNE (measured by selective ion monitoring) in 7 out 10 patients studied. When HNE was quantitated by selective ion monitoring, with reference to a pure standard of HNE and an internal standard of nonanoic acid, ARDS patients showed significantly increased levels of HNE (0.412 +/- 0.023 nmol/ml) compared with normal healthy controls (0.205 +/- 0.018 nmol/ml).

Topics: Adult; Aldehydes; Free Radicals; Gas Chromatography-Mass Spectrometry; Humans; Linoleic Acid; Linoleic Acids; Regression Analysis; Respiratory Distress Syndrome

Patients with the acute lung injury syndrome ARDS are under oxidative stress from the disease and from treatment with high inspired oxygen concentrations. Oxidative stress can lead to molecular damage by a variety of reactive oxygen intermediates generated in the lung. In the present study we sequentially monitor changes in plasma total lipid linoleic acid fatty acid levels, using GC-MS, and express these as a function of changes in plasma protein thiol values. In nine out of eleven ARDS patients there was a relationship between loss of protein thiols and loss of total lipid linoleic acid. In three patients changes in protein thiols preceded changes in total lipid linoleic acid by several days. Parallel decreases in plasma total lipid fatty acid esters of linoleic acid and protein thiols are suggestive of oxidative stress leading to molecular damage.

Topics: Blood Proteins; Fatty Acids; Gas Chromatography-Mass Spectrometry; Humans; Linoleic Acid; Linoleic Acids; Oxidation-Reduction; Respiratory Distress Syndrome; Spectrometry, Fluorescence; Sulfhydryl Compounds; Thiobarbituric Acid Reactive Substances