Document Detail


The pathophysiology of portal hypertension.
MedLine Citation:
PMID:  15920320     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
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.
Authors:
Gerhard Treiber; Antal Csepregi; Peter Malfertheiner
Publication Detail:
Type:  Journal Article; Review    
Journal Detail:
Title:  Digestive diseases (Basel, Switzerland)     Volume:  23     ISSN:  0257-2753     ISO Abbreviation:  Dig Dis     Publication Date:  2005  
Date Detail:
Created Date:  2005-05-27     Completed Date:  2005-08-16     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8701186     Medline TA:  Dig Dis     Country:  Switzerland    
Other Details:
Languages:  eng     Pagination:  6-10     Citation Subset:  IM    
Copyright Information:
2005 S. Karger AG, Basel
Affiliation:
Department of Gastroenterology, Hepatology, and Infectious Diseases, University Hospital Magdeburg, Magdeburg, Germany. gerhard.treiber@medizin.uni-magdeburg.de
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MeSH Terms
Descriptor/Qualifier:
Humans
Hypertension, Portal / metabolism*,  physiopathology*
Liver / anatomy & histology,  blood supply*
Regional Blood Flow
Vasoconstriction
Vasodilation

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