Document Detail

Time course of cardiovascular and hematological responses in rats exposed to chronic intermittent hypobaric hypoxia (4600 m).
MedLine Citation:
PMID:  16544969     Owner:  NLM     Status:  MEDLINE    
The aim of this study was to evaluate the effects of two periods of intermittent exposure to hypoxia (428 torr) in rats over 12 months. The conditions of CIH4x4 (4 days in hypoxia, 4 days in normoxia, n = 50) and CIH2x2 (2 days in hypoxia, 2 days in normoxia, n = 50) were selected for simulating in this animal model the chronic-intermittent exposure to high altitudes experienced by Andean miners. We assessed mortality, weight, hematological parameters, and time course of resting heart rate and systolic blood pressure. In general, mortality increased during the first month, with a tendency to stabilize during exposure; it was associated with lower weights and with higher hematocrit levels, making these possible predictor factors. Intermittence produced an increase in hematocrit and hemoglobin concentrations as previously seen in most hypoxic models, compared with normoxia (NX, n = 30), but attained lower levels compared with chronic hypoxia (CH, n = 28). CIH4x4 and CIH2x2 had similar sustained elevations of systolic blood pressure (171 +/- 3 and 174 +/- 2 mmHg, respectively) versus the basal level (163 +/- 3; 163 +/- 3 mmHg), whereas CH did not. Heart rate suffered an equally sustained decrease in all exposed groups (343 +/- 14 beats/min). Exposure to chronic-intermittent hypoxia led to a mild polycythemia and to a decrease in heart rate. The effects of hypoxia were already evident during the first month of exposure and attained a more pronounced expression and stabilization during the third month.
Patricia Siqués; Julio Brito; Fabiola León-Velarde; Luis Barrios; Juan José De La Cruz; Vasthi López; Rafael Herruzo
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  High altitude medicine & biology     Volume:  7     ISSN:  1527-0297     ISO Abbreviation:  High Alt. Med. Biol.     Publication Date:  2006  
Date Detail:
Created Date:  2006-03-20     Completed Date:  2006-09-14     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  100901183     Medline TA:  High Alt Med Biol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  72-80     Citation Subset:  IM; S    
Instituto de Estudios de Salud, Universidad Arturo Prat, Chile., Centro de Investigaciones del Hombre en el Desierto, Chile.
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MeSH Terms
Altitude Sickness / blood,  complications*,  physiopathology*
Body Weight
Cardiovascular Diseases / etiology*
Chronic Disease
Disease Models, Animal
Environmental Exposure
Heart Rate
Longitudinal Studies
Physical Conditioning, Animal*
Polycythemia / etiology
Rats, Wistar

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