Upregulation of arginase expression and activity in hypertensive rats exposed to chronic intermittent hypobaric hypoxia
| Autor: | Carmen Vallejos, Vasthi Lopez, Patricia Siques, Nelson Carvajal, Nelson Naveas, Fabiola León-Velarde, Julio Brito, Claudia Carvallo |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2009 |
| Předmět: |
Male
medicine.medical_specialty Physiology Acclimatization Blood Pressure Hematocrit Biology Heart Rate Internal medicine Heart rate medicine Animals Rats Wistar Hypoxia Lung Nitrites Nitrates Arginase medicine.diagnostic_test Altitude Myocardium Body Weight Public Health Environmental and Occupational Health Intermittent hypoxia General Medicine Hypoxia (medical) Rats Up-Regulation Atmospheric Pressure medicine.anatomical_structure Endocrinology Blood pressure Hypobaric chamber Hypertension medicine.symptom |
| Zdroj: | HIGH ALTITUDE MEDICINE & BIOLOGY Artículos CONICYT CONICYT Chile instacron:CONICYT |
| Popis: | The aim of this study was to analyze the activity and expression levels of arginase I and II and to monitor the cardiovascular and hematological responses in tolerant and intolerant rats exposed to chronic intermittent hypobaric hypoxia (CIHH). Male Wistar rats (age: 3.0 +/- 0.4 months, weight: 250 +/- 25 g; n = 30) were randomly divided into two groups: CIHH2 x 2 (2 days hypoxia, 2 days normoxia, n = 20) and NX (normoxia, n = 10). The hypoxia was simulated in a hypobaric chamber at 428 torr. Tolerance was determined according to a previous protocol. Arginase activity was measured in lung and heart tissues, and the expression levels were determined by a (RT-PCR) assay in lung tissue. Results showed that the intolerants rats had lower body weight, higher hematocrit (Hct) (74 +/- 4% vs. 61 +/- 2%, p0.05), higher values of systolic blood pressure (SBP) (183 +/- 3.7 mmHg vs. 147 +/- 5.4 mmHg, p0.05), and higher arginase activity. In addition, RT-PCR analysis from lung tissue showed an overexpression of arginase II in the intolerant group (p0.01). However, tolerants had similar values as the NX group (p = ns). Further, a correlation was found between arginase activity and SBP in the heart (r(2) = 0.596, p0.001). An upregulation of arginase type II could be pivotal in understanding the pathogenesis of systolic hypertension and probably other phenomena associated with intermittent hypobaric hypoxia. A schematic explanation of these relations is proposed. |
| Databáze: | OpenAIRE |
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