Mechanism of superoxide anion production by hepatic sinusoidal endothelial cells and Kupffer cells during short-term ethanol perfusion in the rat.
OBJECTIVE
The aim of this study was to clarify the candidate cells for and the mechanism of superoxide anion (O2*-) release into the hepatic sinusoids during short-term exposure to ethanol.


METHODS
The rat liver was perfused continuously with ethanol (a substrate for alcohol dehydrogenase) or tert-buthanol (not a substrate for alcohol dehydrogenase) for 20 min at a final concentration of 40 mM. In order to detect O2*- production, MCLA (2-methyl-6-[p-methoxyphenyl]-3,7-dihydroimidazo[1,2-a]pyrazin-3-one), a Cypridina luciferin analogue, was simultaneously infused and MCLA-enhanced chemiluminescence was measured. The effects of gadolinium chloride (GdCL3) (a suppressor of Kupffer cells (KCs)), staurosporine (ST) (an inhibitor of serine-threonine kinases, including protein kinase C), diphenyleneiodonium chloride (DPI) (an inhibitor of NADPH oxidase), ibuprofen (IB) (an inhibitor of cyclooxygenase) and 4-methylpyrazole (4MP) (an inhibitor of ethanol metabolism) on the ethanol-induced chemiluminescence were also evaluated. Sites where O2*- could be released were determined by histochemical detection of nitro blue tetrazolium reduction.


RESULTS
Both ethanol and tert-buthanol rapidly caused O2*- release. GdCL3 suppressed the ethanol-induced O2*- release by 61%. Staurosporine and DPI, but neither IB nor 4-MP, also significantly inhibited the ethanol-induced O2*- release. In the histochemical examination, ethanol-stimulated liver showed blue formazan precipitate on both sinusoidal endothelial cells (SECs) and Kupffer cells (KCs), whereas the GdCl3-pretreated liver had the precipitate only on SECs.


CONCLUSIONS
This study shows that ethanol itself stimulates both SECs and KCs to release O2*- via activation of NADPH oxidase probably involving protein kinase C (PKC).
Hasegawa
Tadashi
T
First Department of Surgery, Gunma University School of Medicine, Maebashi, Japan. tahasega@showa.gunma-u.ac.jp
Kikuyama
Masataka
M
Sakurai
Kazushi
K
Kambayashi
Yasuhiro
Y
Adachi
Masakazu
M
Saniabadi
Abby R
AR
Kuwano
Hiroyuki
H
Nakano
Minoru
M
D000818:Animals; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D000431:Ethanol / Q000008:administration & dosage / Q000633:toxicity*; D000077604:Fomepizole; D005682:Gadolinium / Q000494:pharmacology; D007052:Ibuprofen / Q000494:pharmacology; D007093:Imidazoles / Q000378:metabolism; D007728:Kupffer Cells / Q000187:drug effects / Q000378:metabolism*; D008163:Luminescent Measurements; D008297:Male; D009580:Nitroblue Tetrazolium / Q000378:metabolism; D009861:Onium Compounds / Q000494:pharmacology; D010477:Perfusion; D011719:Pyrazines / Q000378:metabolism; D011720:Pyrazoles / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D019311:Staurosporine / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism*; D020002:tert-Butyl Alcohol / Q000008:administration & dosage / Q000494:pharmacology
D004791:Enzyme Inhibitors; D007093:Imidazoles; D009861:Onium Compounds; D011719:Pyrazines; D011720:Pyrazoles; D013481:Superoxides; C063412:2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo(1,2-alpha)pyrazin-3-one; D009580:Nitroblue Tetrazolium; D000431:Ethanol; C007517:diphenyleneiodonium; D000077604:Fomepizole; D005682:Gadolinium; D019311:Staurosporine; D020002:tert-Butyl Alcohol; C038958:gadolinium chloride; D007052:Ibuprofen