Free radical generation, lipid peroxidation and essential fatty acids in patients with septicemia.

Infections due to gram-negative bacteria and other organisms can lead to septicemia and shock in some patients. Endotoxins, which cause these pathophysiological events, stimulate macrophages to elaborate tumor necrosis factor and other lymphokines. These lymphokines can augment free radical generation by polymorphonuclear leukocytes, macrophages and other cells, which may ultimately produce respiratory distress syndrome, multiorgan failure and irreversible shock seen in septicemia. This is supported by our results presented here that there is indeed an increase in free radical generation and lipid peroxidation in patients with septicemia. In addition, analysis of plasma lipid profile in these patients showed that gamma-linolenic, dihomogamma-linolenic and arachidonic acids of n-6 series and alpha-linolenic and eicosapentaenoic acids of the n-3 series are decreased in their plasma phospholipid fraction. These results suggest that free radicals, lipid peroxides, and alteration in essential fatty acid metabolism may have a role in the pathogenesis of septicemia.