Acclimatization of low altitude-bred deer mice (Peromyscus maniculatus) to high altitude
| Autor: | Cuneyt Yilmaz, Connie C. W. Hsia, Catherine D. Thaler, D. Merrill Dane, Jamie Dolan, Priya Ravikumar, Khoa Cao, Kimberly A. Hammond, Hua Lu |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
030110 physiology
0301 basic medicine Male Peromyscus Biometry Physiology Acclimatization Zoology 03 medical and health sciences Physiology (medical) medicine Extreme environment Animals Lung Low altitude biology Altitude Respiration Organ Size Effects of high altitude on humans Hypoxia (medical) biology.organism_classification Respiratory Function Tests 030104 developmental biology medicine.symptom Research Article |
| Popis: | A colony of deer mice subspecies ( Peromyscus maniculatus sonoriensis) native to high altitude (HA) has been maintained at sea level for 18–20 generations and remains genetically unchanged. To determine if these animals retain responsiveness to hypoxia, one group (9–11 wk old) was acclimated to HA (3,800 m) for 8 wk. Age-matched control animals were acclimated to a lower altitude (LA; 252 m). Maximal O2uptake (V̇o2max) was measured at the respective altitudes. On a separate day, lung volume, diffusing capacity for carbon monoxide (DLCO), and pulmonary blood flow were measured under anesthesia using a rebreathing technique at two inspired O2tensions. The HA-acclimated deer mice maintained a normal V̇o2maxrelative to LA baseline. Compared with LA control mice, antemortem lung volume was larger in HA mice in a manner dependent on alveolar O2tension. Systemic hematocrit, pulmonary blood flow, and standardized DLCOdid not differ significantly between groups. HA mice showed a higher postmortem alveolar-capillary hematocrit, larger alveolar ducts, and smaller distal conducting structures. In HA mice, absolute volumes of alveolar type I epithelia and endothelia were higher whereas that of interstitia was lower than in LA mice. These structural changes occurred without a net increase in whole-lung septal tissue-capillary volumes or surface areas. Thus, deer mice bred and raised to adulthood at LA retain phenotypic plasticity and adapt to HA without a decrement in V̇o2maxvia structural (enlarged airspaces, alveolar septal remodeling) and nonstructural (lung expansion under hypoxia) mechanisms and without an increase in systemic hematocrit or compensatory lung growth.NEW & NOTEWORTHY Deer mice ( Peromyscus maniculatus) are robust and very active mammals that are found across the North American continent. They are also highly adaptable to extreme environments. When introduced to high altitude they retain remarkable adaptive ability to the low-oxygen environment via lung expansion and remodeling of existing lung structure, thereby maintaining normal aerobic capacity without generating more red blood cells or additional lung tissue. |
| Databáze: | OpenAIRE |
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