Alcohol-Induced Exacerbation of Ischemic Brain Injury: Role of NAD(P)H Oxidase

Authors

  • Honggang Zhao,

    1. From the Department of Cellular and Integrative Physiology (HZ, WGM, DMA, HS) and the Department of Surgery (WX), University of Nebraska Medical Center, Omaha, Nebraska.
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  • William G. Mayhan,

    1. From the Department of Cellular and Integrative Physiology (HZ, WGM, DMA, HS) and the Department of Surgery (WX), University of Nebraska Medical Center, Omaha, Nebraska.
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  • Denise M. Arrick,

    1. From the Department of Cellular and Integrative Physiology (HZ, WGM, DMA, HS) and the Department of Surgery (WX), University of Nebraska Medical Center, Omaha, Nebraska.
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  • Wanfen Xiong,

    1. From the Department of Cellular and Integrative Physiology (HZ, WGM, DMA, HS) and the Department of Surgery (WX), University of Nebraska Medical Center, Omaha, Nebraska.
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  • Hong Sun

    1. From the Department of Cellular and Integrative Physiology (HZ, WGM, DMA, HS) and the Department of Surgery (WX), University of Nebraska Medical Center, Omaha, Nebraska.
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Reprint requests: Hong Sun, MD, PhD, Department of Cellular and Integrative Physiology, 985850 Nebraska Medical Center, University of Nebraska Medical Center, Omaha, Nebraska 68198-5850; Tel: 402-559-5040; Fax: 402-559-4438; E-mail: hsu1@unmc.edu

Abstract

Background:  Chronic alcohol consumption increases ischemic stroke and exacerbates ischemic brain injury. We determined the role of NAD(P)H oxidase in exacerbated ischemic brain injury during chronic alcohol consumption.

Methods:  Sprague Dawley rats were fed a liquid diet with or without alcohol (6.4% v/v) for 8 weeks. We measured the effect of apocynin on 2-hour middle cerebral artery occlusion (MCAO)/24-hour reperfusion-induced brain injury. In addition, superoxide production and expression of NAD(P)H oxidase subunit, gp91phox, in the peri-infarct area were assessed.

Results:  Chronic alcohol consumption produced a larger infarct volume, worse neurological score, and higher superoxide production. Acute (5 mg/kg, ip, 30 minutes before MCAO) and chronic treatment with apocynin (7.5 mg/kg/d in the diet, 4 weeks prior to MCAO) reduced infarct volume, improved neurological outcome, and attenuated superoxide production in alcohol-fed rats. Expression of gp91phox at basal conditions and following ischemia/reperfusion was greater in alcohol-fed rats compared to non-alcohol-fed rats. In addition, neurons are partially responsible for upregulated gp91phox during alcohol consumption.

Conclusions:  Our findings suggest that NAD(P)H oxidase may play an important role in exacerbated ischemic brain injury during chronic alcohol consumption.

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