Fig. 1.
Increased lipid but not protein oxidation in heme oxygenase-2 knockout (HO2 −/−) animals. (A) Increased lipid oxidation product 4-hydroxynonenal (4-HNE) in HO2 (−/−) hippocampus. Data represent mean ± SEM from 4 samples. *, P < 0.001 by t test. (B and C) Similar levels of protein carbonyls, a measure of protein oxidation, in wild-type and HO2 (−/−) animals. Liver (B) and brain (C) were homogenized from 6-month-old male wild-type and HO2 (−/−) animals and protein carbonyls were determined by derivatization with 2,4-dinitrophenylhydrazine (DNPH). To verify measurement of increased carbonyls, samples were treated 30 min with 1 mM tert-butyl hydroperoxide (TBH). Means ± SEM are shown for 4 animals from 2 independent studies.