[Protective effect of losartan on injury induced by ox-LDL in endothelial cells and the relationship with asymmetric dimethylarginine].
OBJECTIVE
To investigate the protective effect of losartan against on injury induced by ox-LDL in endothelial cells and the relationship with asymmetric dimethylarginine (ADMA).


METHODS
Endothelial injury was induced by incubation with ox-LDL 100 mg/L in cultured HUVECs for 24 h, and the levels of ADMA, lactate dehydrogenase (LDH), nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) in the conditioned medium were measured. The activity of dimethylarginine dimethylaminohydrolase (DDAH) of cultured endothelial cells was also determined.


RESULTS
Incubation of endothelial cells with ox-LDL 100 mg/L for 24 h induced a marked elevation of the levels of ADMA, LDH and TNF-alpha in the conditioned medium and a significant decrease in the activity of DDAH and the content of NO (P < 0.05). Pretreatment with losartan (10(-8) - 10(-6) mmol/L) significantly inhibited the increased levels of ADMA, LDH and TNF-alpha, attenuated the decreased levels of NO and the decreased activity of DDAH induced by ox-LDL (P < 0.05).


CONCLUSIONS
Losartan may preserve ox-LDL-induced endothelial cell injury by increasing the DDAH activity and decreasing the ADMA level.
Department of Cardiolog, Xiangya Hospital, Central Soutth University, Changsha 410008, China.
Qi-ying
QY
Xie
Ze-lin
ZL
Sun
Mei-fang
MF
Chen
Tian-lun
TL
Yang
D000581:Amidohydrolases / Q000378:metabolism; D001120:Arginine / Q000031:analogs & derivatives* / Q000032:analysis; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000473:pathology*; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D008077:Lipoproteins, LDL / Q000009:adverse effects*; D019808:Losartan / Q000494:pharmacology*; D009569:Nitric Oxide / Q000032:analysis; D020011:Protective Agents / Q000494:pharmacology; D014471:Umbilical Veins / Q000166:cytology
D008077:Lipoproteins, LDL; D020011:Protective Agents; C099252:oxidized low density lipoprotein; D009569:Nitric Oxide; C018524:N,N-dimethylarginine; D001120:Arginine; D007770:L-Lactate Dehydrogenase; D000581:Amidohydrolases; C059999:dimethylargininase; D019808:Losartan