Document Detail


Abnormal renal function and autoregulation in essential hypertension.
MedLine Citation:
PMID:  1937686     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The goal of this presentation has been to emphasize two fundamental mechanisms in the development of essential hypertension. These are: 1) The basic cause of essential hypertension is the inability of the kidneys to excrete an adequate volume of urine at normal arterial pressure. Therefore, fluid accumulates in the body until the pressure rises high enough to balance fluid output with fluid intake. This fluid balancing act is an infinite gain feedback system for controlling arterial pressure to a very precise level determined by the kidneys. Furthermore, this infinite gain allows the kidney mechanism to dominate the other pressure control mechanisms for long-term pressure control. Because of this domination, as long as a person has normal intake of water and electrolytes, essential hypertension cannot develop without an elevated pressure setting of the kidneys. 2) An increase in total peripheral resistance will not cause hypertension as long as the kidneys can still excrete normal amounts of water and electrolytes at normal arterial pressure, because loss of excess fluid volume at high pressures will simply reduce the cardiac output until the pressure falls back to normal. Therefore, what is the cause of the very high total peripheral resistance found in almost all patients with essential hypertension? The answer is likely the long-term blood flow autoregulation mechanism that occurs in virtually all tissues of the body. That is, when the pressure rises too high for whatever reason, this in turn forces too much blood flow through the tissues. In response, the local blood flow control mechanisms all over the body increase the vascular resistances until the flows return to normal.(ABSTRACT TRUNCATED AT 250 WORDS)
Authors:
A C Guyton
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Hypertension     Volume:  18     ISSN:  0194-911X     ISO Abbreviation:  Hypertension     Publication Date:  1991 Nov 
Date Detail:
Created Date:  1991-12-26     Completed Date:  1991-12-26     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  7906255     Medline TA:  Hypertension     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  III49-53     Citation Subset:  IM    
Affiliation:
Department of Physiology and Biophysics, University of Mississippi School of Medicine, Jackson 39216.
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MeSH Terms
Descriptor/Qualifier:
Blood Pressure
Extracellular Space / physiology
Feedback
Homeostasis*
Humans
Hypertension / physiopathology*
Kidney / physiopathology*
Vascular Resistance

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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