High metabolic rates of 4-hydroxynonenal in brain capillary endothelial cells during hypoxia/reoxygenation.
We measured the accumulation of 4-hydroxynonenal (HNE), a major lipid peroxidation product during hypoxia/reoxygenation of brain capillary endothelial cells (BCEC). The concentration of HNE after 2 h of hypoxia was 0.23 nmol/mg protein and rose up to 0.28 nmol/mg protein after 30 min of reoxygenation. That reflects a 1.5-fold increase, whereas aortic endothelial cells (AEC) increased the HNE level 5-fold, compared to the control. Therefore, the ability of BCEC to degrade exogenously added HNE was tested. The HNE consumption in BCEC achieved a rate of about 600 nmol.min-1.mg protein-1, about two times higher than in AEC. The higher ability of BCEC to degrade HNE is probably the reason of the 2-fold higher IC50 value against the aldehyde. Therefore, we concluded that the high ability of BCEC to degrade HNE is a substantial part of the secondary antioxidative defense of the brain.
Kunstmann
S
S
Clinics of Physical Medicine and Rehabilitation, Medical Faculty (Charité), Humboldt University, Berlin, Germany.
Mertsch
K
K
Blasig
I E
IE
Grune
T
T
D000447:Aldehydes / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002196:Capillaries / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004727:Endothelium / Q000378:metabolism; D000860:Hypoxia / Q000503:physiopathology*; D010100:Oxygen / Q000502:physiology*
D000447:Aldehydes; C027576:4-hydroxy-2-nonenal; D010100:Oxygen