| The pathophysiology of portal hypertension. | |
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MedLine Citation:
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PMID: 15920320 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Portal hypertension is defined by an elevation in blood pressure in the portal system. Different causes are known and include a pre-, intra-, or posthepatic block. Portal hypertension is also classified according to the sinusoidal system. Portal pressure becomes elevated by either an increase in blood flow (Q), an increase in resistance (R), or both. Regulation of the vascular tone in the splanchnic system includes intrinsic and extrinsic aspects. A variety of metabolic end-products (e.g. adenosine), endothelium-derived substances (e.g. nitric oxide), and certain neurotransmitters (e.g. acetylcholine) are known to relax the tone and thus produce vasodilation. Important vasoconstrictor influences on splanchnic arterioles include circulating agents (e.g. angiotensin), endothelium-derived substances (e.g. endothelin), and again neurotransmitters (norepinephrine). Besides vascular tone, structural changes (thrombosis, fibrosis, shear stress, and cell regeneration) add to overall hepatic resistance. Further consequences of portal hypertension include an increase in blood flow which leads to a hyperdynamic state with fluid retention, leading to secondary involvement of other organs, such as cirrhotic cardiomyopathy, hepatopulmonary syndrome and hepatorenal syndrome. Finally, portal hypertension will end up in the formation of collateral vessels. Varices can involve the whole gastrointestinal tract and are a frequent source of bleeding. |
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Authors:
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Gerhard Treiber; Antal Csepregi; Peter Malfertheiner |
Publication Detail:
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Type: Journal Article; Review |
Journal Detail:
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Title: Digestive diseases (Basel, Switzerland) Volume: 23 ISSN: 0257-2753 ISO Abbreviation: Dig Dis Publication Date: 2005 |
Date Detail:
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Created Date: 2005-05-27 Completed Date: 2005-08-16 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 8701186 Medline TA: Dig Dis Country: Switzerland |
Other Details:
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Languages: eng Pagination: 6-10 Citation Subset: IM |
Copyright Information:
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2005 S. Karger AG, Basel |
Affiliation:
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Department of Gastroenterology, Hepatology, and Infectious Diseases, University Hospital Magdeburg, Magdeburg, Germany. gerhard.treiber@medizin.uni-magdeburg.de |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Humans Hypertension, Portal / metabolism*, physiopathology* Liver / anatomy & histology, blood supply* Regional Blood Flow Vasoconstriction Vasodilation |
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