Detection of 4-hydroxynonenal as a product of lipid peroxidation in native Ehrlich ascites tumor cells.

4-Hydroxynonenal, which is a major product of lipid peroxidation in rat liver microsomes, was detected in native Ehrlich ascites tumor cells. Its formation was stimulated either by ferrous ions or by Fe(II)-histidinate. The identification was based on chromatographic (TLC/HPLC) and ultraviolet-spectroscopic evidence using synthetic 4-hydroxynonenal as reference. Highest values of 4-hydroxynonenal concentration (about 0.1 microM in the cell suspension) after 30 min of incubation were observed with Fe(II)-histidinate as stimulant. Saturation was already reached after an incubation period of 10 min. The results confirm the expectation by Schauenstein and Esterbauer (in Submolecular Biology and Cancer, Ciba Foundation Series 67 (1979) pp. 225-244, Excerpta Medica, Amsterdam) that endogenous lipid peroxidation gives rise to a distinct intracellular level of alpha, beta-unsaturated aldehydes. A simple hypothetical mechanism for the formation of 4-hydroxynonenal from n-6-polyunsaturated fatty acids is presented.