Fatty acid profiles and non enzymatic lipid peroxidation of microsomes and mitochondria from bovine liver, kidney, lung and heart.

The light emission = chemiluminescence and fatty acid composition, two markers of lipid peroxidation process, was evaluated in bovine liver, kidney, lung and heart microsomes and mitochondria incubated in the presence of ascorbate-Fe2+ at 37 degrees C. Microsomal and mitochondrial fractions obtained from lung, kidney and heart were more resistant to lipid peroxidation than those isolated from the liver. The ascorbate-Fe2+ seemed to be totally ineffective in stimulating peroxidation of bovine lung, heart and kidney microsomes or mitochondria. Whereas bovine liver microsomes or mitochondria displayed the highest values of chemiluminescence when incubated in the presence of ascorbate-Fe2+. The peroxidizability index a parameter that indicate the maximal rate of oxidation of specific fatty acids showed statistically significant differences in mitochondria isolated from lung heart and kidney and microsomes isolated from lung. The fatty acid profile of the subcellular fractions obtained from those tissues do not appear to be responsible for their different susceptibility to free radical degradation. Other factor/s may be responsible for the protection to lipid peroxidation observed in microsomal or mitochondrial fractions obtained from bovine lung, heart and kidney.