Role of NAD(P)H oxidase in alcohol-induced impairment of endothelial nitric oxide synthase-dependent dilation of cerebral arterioles.
OBJECTIVE
Our goal was to determine whether NAD(P)H oxidase is involved in impaired endothelial nitric oxide synthase (eNOS)-dependent reactivity of cerebral arterioles during chronic alcohol consumption.


METHODS
Sprague-Dawley rats were fed with an alcohol diet for 2 to 3 months. We determined the effects of acute and chronic treatment with an NAD(P)H oxidase inhibitor, apocynin, on responses of pial arterioles to eNOS-dependent agonists (acetylcholine and ADP) and an eNOS-independent agonist (nitroglycerin). Expression of NAD(P)H oxidase in pial arterioles was measured with the use of real-time polymerase chain reaction and Western blot analysis, and superoxide production was measured with the use of lucigenin-enhanced chemiluminescence.


RESULTS
Vasodilation in response to acetylcholine and ADP, but not nitroglycerin, was significantly less in alcohol-fed rats. Treatment with apocynin did not alter vasodilation in non-alcohol-fed rats but significantly improved impaired vasodilation in alcohol-fed rats. In addition, an upregulation of p47phox in pial arterioles was found in alcohol-fed rats. Furthermore, alcohol consumption increased superoxide production under basal conditions and in the presence of ADP and NAD(P)H.


CONCLUSIONS
Our findings suggest that NAD(P)H oxidase plays a role in chronic alcohol consumption-induced impairment of eNOS-dependent dilation of cerebral arterioles.
Sun
Hong
H
Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198-5850, USA. hsu1@unmc.edu
Zheng
Hong
H
Molacek
Elizabeth
E
Fang
Qin
Q
Patel
Kaushik P
KP
Mayhan
William G
WG
D000098:Acetophenones / Q000494:pharmacology; D000109:Acetylcholine / Q000494:pharmacology; D000166:Acridines / Q000494:pharmacology; D000244:Adenosine Diphosphate / Q000737:chemistry; D000428:Alcohol Drinking; D000438:Alcohols / Q000494:pharmacology*; D000818:Animals; D015153:Blotting, Western; D001835:Body Weight; D002492:Central Nervous System Depressants / Q000494:pharmacology; D002536:Cerebral Arteries / Q000473:pathology*; D002560:Cerebrovascular Circulation; D004108:Dilatation, Pathologic / Q000473:pathology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D049449:Luminescence; D008297:Male; D015233:Models, Statistical; D019255:NADPH Oxidases / Q000378:metabolism / Q000502:physiology*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D005996:Nitroglycerin / Q000494:pharmacology; D010750:Phosphoproteins / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020521:Stroke / Q000473:pathology; D013481:Superoxides / Q000378:metabolism; D013997:Time Factors; D015854:Up-Regulation; D014664:Vasodilation; D014665:Vasodilator Agents / Q000494:pharmacology
D000098:Acetophenones; D000166:Acridines; D000438:Alcohols; D002492:Central Nervous System Depressants; D004791:Enzyme Inhibitors; D010750:Phosphoproteins; D014665:Vasodilator Agents; D013481:Superoxides; C033472:10,10'-dimethyl-9,9'-biacridinium; D000244:Adenosine Diphosphate; C056165:acetovanillone; D052250:Nitric Oxide Synthase Type III; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; D005996:Nitroglycerin; D000109:Acetylcholine