Document Detail

Hyponatremia with hypoxia: effects on brain adaptation, perfusion, and histology in rodents.
MedLine Citation:
PMID:  16614721     Owner:  NLM     Status:  MEDLINE    
Hypoxia appears to be a prominent component of brain damage among patients with hyponatremic encephalopathy. Effects of hypoxia on brain in the presence of hyponatremia are not known. In order to evaluate the contributions of hypoxia to brain damage, three separate experiments were conducted in three groups of rodents. Experiment I evaluated the effects of hypoxia and acute (< 4 h) hyponatremia (plasma Na < 120 mmol/l) on brain adaptation in rabbits. Experiment II evaluated the effects of hypoxia and chronic (4 days) hyponatremia on cerebral perfusion in rats. Experiment III evaluated the effects of hypoxia and chronic hyponatremia on brain histology in rats. In experiment I, rabbits with acute hyponatremia demonstrated brain adaptation with significant falls in brain Na content (by 14.2%, P < 0.01) and osmolality (by 8.3%, P < 0.01), and a rise in brain water (by 10.6%, P < 0.05). Rabbits with combined hypoxia and hyponatremia failed to demonstrate brain adaptation. In experiment II, rats with chronic hyponatremia plus hypoxia had a decrease in cerebral perfusion index by more than 50% (P < 0.01). In experiment III, 23% of hypoxic rats had brain lesions, which were in the cerebellum, thalamus, reticular formation, and basal ganglia. Hyponatremia without hypoxia resulted in no brain lesions. Hypoxia in normonatremic animals results in cerebral edema and histopathologic lesions similar to those found in rats whose plasma Na was overcorrected. Hypoxia in hyponatremic animals aggravates cerebral edema, impairs brain adaptation, and decreases cerebral perfusion.
J C Ayus; D Armstrong; A I Arieff
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, N.I.H., Extramural    
Journal Detail:
Title:  Kidney international     Volume:  69     ISSN:  0085-2538     ISO Abbreviation:  Kidney Int.     Publication Date:  2006 Apr 
Date Detail:
Created Date:  2006-04-14     Completed Date:  2006-06-22     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0323470     Medline TA:  Kidney Int     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1319-25     Citation Subset:  IM    
Department of Medicine, University of Texas Health Sciences Center, San Antonio, 78229, USA.
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MeSH Terms
Adaptation, Physiological*
Brain / metabolism,  pathology*
Brain Damage, Chronic / etiology,  pathology*
Hyponatremia / complications,  mortality,  pathology*
Hypoxia, Brain / complications*,  etiology,  pathology
Magnetic Resonance Imaging
Models, Anatomic
Rats, Sprague-Dawley
Grant Support
R01 AG 08575-01A2/AG/NIA NIH HHS
Comment In:
Kidney Int. 2006 Apr;69(8):1291-3   [PMID:  16614718 ]

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