Effects of ethanol and acetaldehyde on reactive oxygen species production in rat hepatic stellate cells.
BACKGROUND
Alcoholism is a common cause of cirrhosis. Hepatic stellate cells are the main source of collagen that ultimately leads to hepatic fibrosis and cirrhosis. Reactive oxygen species (ROS) enhance stellate cell activation and stimulate fibrogenesis. In this study, the acute effects of ethanol (ET) and acetaldehyde (AC) were determined on the production of ROS in isolated rat hepatic stellate cells.


METHODS
Rat stellate cells were isolated in situ by perfusion of the portal vein and cultured. Hydrogen peroxide (H(2)O(2)) was determined by luminol-derived chemiluminescence (CL), while superoxide anion (O(2*-)) production was assessed by the fluorescent probe hydroethidine.


RESULTS
AC increased the formation of H(2)O(2) and O(2*-), and these effects were first detectable at AC concentrations of 5 and 10 microM, respectively, reaching a maximum at 50 to 75 microM. Reduction of glutathione (GSH) synthesis by 1-buthionine sulfoximide (BSO) or by GSH conjugation with dimethylmaleate (DEM) further enhanced the effects of AC on H(2)O(2) and O(2*-) formation, while N-acetylcysteine (NAC) decreased H(2)O(2) and eliminated the enhanced generation of O(2*-) caused by AC. Raloxifene, which inhibits O(2*-) production by NAD(P)H oxidase, reduced the effects of AC on H(2)O(2) and O(2*-) production. ET increased H(2)O(2) or O(2*-) only in the presence of BSO or DEM.


CONCLUSIONS
This study shows that concentrations of AC, which occur in vivo after the ingestion of alcoholic beverages, result in the formation of ROS in rat hepatic stellate cells. The increases in ROS are known to activate stellate cells promoting fibrogenesis.
Novitskiy
Gennadiy
G
Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2195, USA.
Traore
Kassim
K
Wang
Lan
L
Trush
Michael A
MA
Mezey
Esteban
E
D000079:Acetaldehyde / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D000431:Ethanol / Q000008:administration & dosage*; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism*
D004338:Drug Combinations; D017382:Reactive Oxygen Species; D000431:Ethanol; D000079:Acetaldehyde