The Role of Different Components of Oxidized LDL in the Inhibition of Nitric Oxide Production in Macrophages.
The role of different components of oxidized LDL (Ox-LDL) in the inhibition of LPS-induced nitric oxide (NO) production in macrophages was studied by measuring nitrite in the media. The results showed that Ox-LDL was effective, but the native and the acetylated LDL were not. The removal of the lipid hydroperoxides in Ox-LDL by glutathione peroxidase mimic-ebselen had no effect on the inhibition. The protein moiety of Ox-LDL had no effect on NO production, but the lipid moiety was inhibitory. Linoleic acid and phosphatidylcholine, the main components of LDL lipid, oxidized either separately or together, had no effect on NO production, but if linoleic acid was oxidized together with cholesterol there was strong inhibition on NO production. Cholesterol oxidized alone also had some inhibitory effect. These results suggested that the oxycholesterols in Ox-LDL might be responsible for the inhibition of NO production in macrophages.
Liu
Shang-Xi
SX
Research Laboratory of Free Radical Medicine, The First Military Medical University, Guangzhou 510515, China.
Chen
Yuan
Y
Zhou
Mei
M