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dc.contributor.authorZhang, Nan
dc.date.accessioned2010-02-09T22:14:27Z
dc.date.available2010-02-09T22:14:27Z
dc.date.issued2010-02-09T22:14:27Z
dc.date.submittedJuly 2009
dc.identifier.urihttp://hdl.handle.net/1928/10358
dc.description.abstractHigh blood pressure and endothelial dysfunction are two systemic abnormalities of the cardiovascular system that extensively contribute to the etiology of cardiovascular diseases, which represent the number one killer in the United States for decades and become more severe in developing countries. Previous studies have indicated that aryl hydrocarbon receptor (AHR), a transcription factor primarily mediating xenobiotic metabolism, plays an important role in cardiovascular development and physiology. AHR deficient mice have been demonstrated to develop hypotension at sea level and oxygen-dependent, endothelin-1 (ET-1) mediated hypertension at mild altitude. However, after generations at mild altitude, AHR deficient mice appear to acclimate to the lower atmospheric partial pressure of oxygen and exhibit normal levels of ET-1 and hypotension. Therefore, the goal of my research was to elucidate the mechanism by which endogenous AHR regulates blood pressure by studying blood pressure regulation in the absence of the AHR. I found that AHR deficient mice exhibit significantly lower systemic arterial blood pressure, dysregulated circadian blood pressure rhythm, and significantly elevated vascular endothelial nitric oxide synthase (eNOS) expression and systemic production of nitric oxide (NO). I found that treating AHR deficient mice with the NOS inhibitor, Nω-nitro-L-arginine (LNNA) failed to normalize blood pressure, suggesting that vascular eNOS over expression may not be the primary mediating factor of hypotension in AHR knockout mice. Further investigation on vascular activity ex vivo indicated increased sensitivity of vascular smooth muscle to NO which may simultaneously contribute to the hypotension in this scenario. In vitro studies using human aortic endothelial cells with AHR expression knockdown by siRNA suggested an intracellular role of endogenous AHR signaling in suppressing eNOS mRNA expression, which could be normalized by exogenous ligand activation of the residual AHR. My results suggest that AHR suppresses eNOS expression and acts to maintain basal vascular tone and normal blood pressure. Therefore, therapeutic approaches that antagonize AHR signaling could improve NO bioavailability and benefit patients with hypertension and vascular diseases commonly associated with endothelial dysfunction.en_US
dc.language.isoen_USen_US
dc.subjectaryl hydrocarbon receptoren_US
dc.subjectblood pressureen_US
dc.subjectendothelial nitric oxide synthaseen_US
dc.subject.lcshCardiovascular system--Diseases--Etiology
dc.subject.lcshBlood pressure--Regulation
dc.subject.lcshVascular endothelium--Pathophysiology
dc.subject.lcshXenobiotics--Metabolism--Regulation
dc.subject.lcshNitric oxide--Regulation
dc.subject.lcshTranscription factors
dc.titleThe role of aryl hydrocarbon receptor in blood pressure regulation and vascular homeostasisen_US
dc.typeDissertationen_US
dc.description.degreeBiomedical Sciencesen_US
dc.description.levelDoctoralen_US
dc.description.departmentUniversity of New Mexico. Biomedical Sciences Graduate Programen_US
dc.description.advisorWalker, Mary
dc.description.committee-memberKanagy, Nancy
dc.description.committee-memberResta, Tom
dc.description.committee-memberTimmins, Graham


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