Document Detail

Peripheral arterial vasodilation hypothesis of sodium and water retention in pregnancy: implications for pathogenesis of preeclampsia-eclampsia.
MedLine Citation:
PMID:  2002992     Owner:  NLM     Status:  MEDLINE    
Primary peripheral arterial vasodilation with relative underfilling of the arterial circulation occurs in early pregnancy and leads to several consequences, including decreased systolic and diastolic blood pressures, enhanced cardiac output secondary to afterload reduction, stimulation of the renin-angiotensin-aldosterone axis, nonosmotic stimulation of thirst and vasopressin release, and renal sodium and water retention with expansion of the extracellular fluid and plasma volume compartments. These are events known to occur in all states of arterial vasodilation. Pregnancy has, however, several unique features. Primary arterial vasodilation generally is associated with no change or a decrease in renal blood flow and glomerular filtration rate and failure to escape from the sodium-retaining effects of aldosterone. In early pregnancy, renal blood flow and glomerular filtration rate increase by 30-50% in parallel with the peripheral arterial vasodilation but before plasma volume expansion. No known vasodilator exhibits such a profound effect on renal hemodynamics. Vasodilating prostaglandins may contribute to, but cannot explain, this remarkable enhancement of renal hemodynamics in early pregnancy. Therefore, a highly potent, as yet undefined, systemic and renal vasodilator must be unique to pregnancy. The increased glomerular filtration rate and filtered sodium load with enhanced distal tubular sodium delivery allows escape from aldosterone, an effect not observed in other states of arterial underfilling. This vasodilator may also account, at least in part, for the vascular resistance to angiotensin known to occur in normal pregnancy. This hypothesis for the normal physiology of pregnancy sets the stage for understanding the pathogenesis of preeclampsia-eclampsia.(ABSTRACT TRUNCATED AT 250 WORDS)
R W Schrier; V A Briner
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Obstetrics and gynecology     Volume:  77     ISSN:  0029-7844     ISO Abbreviation:  Obstet Gynecol     Publication Date:  1991 Apr 
Date Detail:
Created Date:  1991-04-18     Completed Date:  1991-04-18     Revised Date:  2009-10-26    
Medline Journal Info:
Nlm Unique ID:  0401101     Medline TA:  Obstet Gynecol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  632-9     Citation Subset:  AIM; IM    
Department of Medicine, University of Colorado School of Medicine, Denver.
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MeSH Terms
Blood Volume
Body Water / metabolism
Eclampsia / etiology*
Edema / physiopathology
Glomerular Filtration Rate
Pregnancy / physiology*
Renin-Angiotensin System / physiology
Sodium / metabolism
Vasodilation / physiology*
Reg. No./Substance:
Comment In:
Obstet Gynecol. 1991 Aug;78(2):321-2   [PMID:  2067782 ]

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

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