Aerobic capacity and skeletal muscle properties of normoxic and hypoxic rats in response to training

ISSN:
1432-2013
Keywords:
Key words Capillarization ; Endurance time to exhaustion ; Fast-and slow-twitch skeletal muscles ; Fibre type distribution ; Food restriction ; Oxidative and glycolytic enzymes ; Maximal oxygen uptake
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The aim of this study was to determine, in the rat, the effects of chronic exposure (7–9 weeks) to normobaric hypoxia (FIO2 = 0.13, equivalent to 3700 m altitude) on cardiac and skeletal muscle properties, on maximal oxygen uptake (VO2max), and endurance time to exhaustion (ETE). In addition, we evaluated the impact of endurance training (90 min of treadmill running per day, 5 days per week, for 9 weeks) on these parameters. The results were compared to normoxic rats fed ad libitum (NAL) and to normoxic pair-weight (NPW) animals in order to take into account the influence of hypoxia on growth rate. It was found that, in sedentary rats, hypoxia results in stunted growth, adrenal atrophy, a significant reduction of cross-sectional area of fast-twitch (type II) fibres, a reduced capillary-to-fibre ratio (C/F), and a reduced oxidative capacity (decreases in citrate synthase and 3-hydroxy-Acyl CoA dehydrogenase activities) of the plantaris muscle. These effects are mainly related to the anorexic effects of prolonged exposure to hypoxia. Nevertheless, hypoxic (H) rats displayed higher VO2max and ETE values when compared either to NAL or to NPW animals. Endurance training resulted, in all groups (H, NAL, NPW), in a significant change of the fibre type distribution of the plantaris which displayed an increased number of type IIA fibres and a decreased proportion of type IIB fibres. In addition, the C/F ratio and cross-sectional area of fast-twitch fibres were normalized by superimposition of training on hypoxia. Both VO2max and ETE were significantly higher in trained H rats than in NAL, but these improvements were mainly related to the reduced body weight induced by hypoxia. These data suggest that the greater aerobic capacity and tolerance for prolonged exercise induced by chronic exposure to hypoxia can be mainly accounted for by the anorexic effects of hypoxia, although other factors (e.g. increase in oxygen carrying capacity induced by hypoxia acclimatization) may play a significant role in some circumstances (e.g. in sedentary rats).
Type of Medium:
Electronic Resource
URL:
_version_ 1798295877590188032
autor Abdelmalki, A.
Fimbel, S.
Mayet-Sornay, M. H.
Sempore, B.
Favier, R.
autorsonst Abdelmalki, A.
Fimbel, S.
Mayet-Sornay, M. H.
Sempore, B.
Favier, R.
book_url http://dx.doi.org/10.1007/s004240050051
datenlieferant nat_lic_papers
hauptsatz hsatz_simple
identnr NLM201007258
issn 1432-2013
journal_name Pflügers Archiv
materialart 1
notes Abstract The aim of this study was to determine, in the rat, the effects of chronic exposure (7–9 weeks) to normobaric hypoxia (FIO2 = 0.13, equivalent to 3700 m altitude) on cardiac and skeletal muscle properties, on maximal oxygen uptake (VO2max), and endurance time to exhaustion (ETE). In addition, we evaluated the impact of endurance training (90 min of treadmill running per day, 5 days per week, for 9 weeks) on these parameters. The results were compared to normoxic rats fed ad libitum (NAL) and to normoxic pair-weight (NPW) animals in order to take into account the influence of hypoxia on growth rate. It was found that, in sedentary rats, hypoxia results in stunted growth, adrenal atrophy, a significant reduction of cross-sectional area of fast-twitch (type II) fibres, a reduced capillary-to-fibre ratio (C/F), and a reduced oxidative capacity (decreases in citrate synthase and 3-hydroxy-Acyl CoA dehydrogenase activities) of the plantaris muscle. These effects are mainly related to the anorexic effects of prolonged exposure to hypoxia. Nevertheless, hypoxic (H) rats displayed higher VO2max and ETE values when compared either to NAL or to NPW animals. Endurance training resulted, in all groups (H, NAL, NPW), in a significant change of the fibre type distribution of the plantaris which displayed an increased number of type IIA fibres and a decreased proportion of type IIB fibres. In addition, the C/F ratio and cross-sectional area of fast-twitch fibres were normalized by superimposition of training on hypoxia. Both VO2max and ETE were significantly higher in trained H rats than in NAL, but these improvements were mainly related to the reduced body weight induced by hypoxia. These data suggest that the greater aerobic capacity and tolerance for prolonged exercise induced by chronic exposure to hypoxia can be mainly accounted for by the anorexic effects of hypoxia, although other factors (e.g. increase in oxygen carrying capacity induced by hypoxia acclimatization) may play a significant role in some circumstances (e.g. in sedentary rats).
package_name Springer
publikationsjahr_anzeige 1996
publikationsjahr_facette 1996
publikationsjahr_intervall 8004:1995-1999
publikationsjahr_sort 1996
publisher Springer
reference 431 (1996), S. 671-679
schlagwort Key words Capillarization
Endurance time to exhaustion
Fast-and slow-twitch skeletal muscles
Fibre type distribution
Food restriction
Oxidative and glycolytic enzymes
Maximal oxygen uptake
search_space articles
shingle_author_1 Abdelmalki, A.
Fimbel, S.
Mayet-Sornay, M. H.
Sempore, B.
Favier, R.
shingle_author_2 Abdelmalki, A.
Fimbel, S.
Mayet-Sornay, M. H.
Sempore, B.
Favier, R.
shingle_author_3 Abdelmalki, A.
Fimbel, S.
Mayet-Sornay, M. H.
Sempore, B.
Favier, R.
shingle_author_4 Abdelmalki, A.
Fimbel, S.
Mayet-Sornay, M. H.
Sempore, B.
Favier, R.
shingle_catch_all_1 Abdelmalki, A.
Fimbel, S.
Mayet-Sornay, M. H.
Sempore, B.
Favier, R.
Aerobic capacity and skeletal muscle properties of normoxic and hypoxic rats in response to training
Key words Capillarization
Endurance time to exhaustion
Fast-and slow-twitch skeletal muscles
Fibre type distribution
Food restriction
Oxidative and glycolytic enzymes
Maximal oxygen uptake
Key words Capillarization
Endurance time to exhaustion
Fast-and slow-twitch skeletal muscles
Fibre type distribution
Food restriction
Oxidative and glycolytic enzymes
Maximal oxygen uptake
Abstract The aim of this study was to determine, in the rat, the effects of chronic exposure (7–9 weeks) to normobaric hypoxia (FIO2 = 0.13, equivalent to 3700 m altitude) on cardiac and skeletal muscle properties, on maximal oxygen uptake (VO2max), and endurance time to exhaustion (ETE). In addition, we evaluated the impact of endurance training (90 min of treadmill running per day, 5 days per week, for 9 weeks) on these parameters. The results were compared to normoxic rats fed ad libitum (NAL) and to normoxic pair-weight (NPW) animals in order to take into account the influence of hypoxia on growth rate. It was found that, in sedentary rats, hypoxia results in stunted growth, adrenal atrophy, a significant reduction of cross-sectional area of fast-twitch (type II) fibres, a reduced capillary-to-fibre ratio (C/F), and a reduced oxidative capacity (decreases in citrate synthase and 3-hydroxy-Acyl CoA dehydrogenase activities) of the plantaris muscle. These effects are mainly related to the anorexic effects of prolonged exposure to hypoxia. Nevertheless, hypoxic (H) rats displayed higher VO2max and ETE values when compared either to NAL or to NPW animals. Endurance training resulted, in all groups (H, NAL, NPW), in a significant change of the fibre type distribution of the plantaris which displayed an increased number of type IIA fibres and a decreased proportion of type IIB fibres. In addition, the C/F ratio and cross-sectional area of fast-twitch fibres were normalized by superimposition of training on hypoxia. Both VO2max and ETE were significantly higher in trained H rats than in NAL, but these improvements were mainly related to the reduced body weight induced by hypoxia. These data suggest that the greater aerobic capacity and tolerance for prolonged exercise induced by chronic exposure to hypoxia can be mainly accounted for by the anorexic effects of hypoxia, although other factors (e.g. increase in oxygen carrying capacity induced by hypoxia acclimatization) may play a significant role in some circumstances (e.g. in sedentary rats).
1432-2013
14322013
Springer
shingle_catch_all_2 Abdelmalki, A.
Fimbel, S.
Mayet-Sornay, M. H.
Sempore, B.
Favier, R.
Aerobic capacity and skeletal muscle properties of normoxic and hypoxic rats in response to training
Key words Capillarization
Endurance time to exhaustion
Fast-and slow-twitch skeletal muscles
Fibre type distribution
Food restriction
Oxidative and glycolytic enzymes
Maximal oxygen uptake
Key words Capillarization
Endurance time to exhaustion
Fast-and slow-twitch skeletal muscles
Fibre type distribution
Food restriction
Oxidative and glycolytic enzymes
Maximal oxygen uptake
Abstract The aim of this study was to determine, in the rat, the effects of chronic exposure (7–9 weeks) to normobaric hypoxia (FIO2 = 0.13, equivalent to 3700 m altitude) on cardiac and skeletal muscle properties, on maximal oxygen uptake (VO2max), and endurance time to exhaustion (ETE). In addition, we evaluated the impact of endurance training (90 min of treadmill running per day, 5 days per week, for 9 weeks) on these parameters. The results were compared to normoxic rats fed ad libitum (NAL) and to normoxic pair-weight (NPW) animals in order to take into account the influence of hypoxia on growth rate. It was found that, in sedentary rats, hypoxia results in stunted growth, adrenal atrophy, a significant reduction of cross-sectional area of fast-twitch (type II) fibres, a reduced capillary-to-fibre ratio (C/F), and a reduced oxidative capacity (decreases in citrate synthase and 3-hydroxy-Acyl CoA dehydrogenase activities) of the plantaris muscle. These effects are mainly related to the anorexic effects of prolonged exposure to hypoxia. Nevertheless, hypoxic (H) rats displayed higher VO2max and ETE values when compared either to NAL or to NPW animals. Endurance training resulted, in all groups (H, NAL, NPW), in a significant change of the fibre type distribution of the plantaris which displayed an increased number of type IIA fibres and a decreased proportion of type IIB fibres. In addition, the C/F ratio and cross-sectional area of fast-twitch fibres were normalized by superimposition of training on hypoxia. Both VO2max and ETE were significantly higher in trained H rats than in NAL, but these improvements were mainly related to the reduced body weight induced by hypoxia. These data suggest that the greater aerobic capacity and tolerance for prolonged exercise induced by chronic exposure to hypoxia can be mainly accounted for by the anorexic effects of hypoxia, although other factors (e.g. increase in oxygen carrying capacity induced by hypoxia acclimatization) may play a significant role in some circumstances (e.g. in sedentary rats).
1432-2013
14322013
Springer
shingle_catch_all_3 Abdelmalki, A.
Fimbel, S.
Mayet-Sornay, M. H.
Sempore, B.
Favier, R.
Aerobic capacity and skeletal muscle properties of normoxic and hypoxic rats in response to training
Key words Capillarization
Endurance time to exhaustion
Fast-and slow-twitch skeletal muscles
Fibre type distribution
Food restriction
Oxidative and glycolytic enzymes
Maximal oxygen uptake
Key words Capillarization
Endurance time to exhaustion
Fast-and slow-twitch skeletal muscles
Fibre type distribution
Food restriction
Oxidative and glycolytic enzymes
Maximal oxygen uptake
Abstract The aim of this study was to determine, in the rat, the effects of chronic exposure (7–9 weeks) to normobaric hypoxia (FIO2 = 0.13, equivalent to 3700 m altitude) on cardiac and skeletal muscle properties, on maximal oxygen uptake (VO2max), and endurance time to exhaustion (ETE). In addition, we evaluated the impact of endurance training (90 min of treadmill running per day, 5 days per week, for 9 weeks) on these parameters. The results were compared to normoxic rats fed ad libitum (NAL) and to normoxic pair-weight (NPW) animals in order to take into account the influence of hypoxia on growth rate. It was found that, in sedentary rats, hypoxia results in stunted growth, adrenal atrophy, a significant reduction of cross-sectional area of fast-twitch (type II) fibres, a reduced capillary-to-fibre ratio (C/F), and a reduced oxidative capacity (decreases in citrate synthase and 3-hydroxy-Acyl CoA dehydrogenase activities) of the plantaris muscle. These effects are mainly related to the anorexic effects of prolonged exposure to hypoxia. Nevertheless, hypoxic (H) rats displayed higher VO2max and ETE values when compared either to NAL or to NPW animals. Endurance training resulted, in all groups (H, NAL, NPW), in a significant change of the fibre type distribution of the plantaris which displayed an increased number of type IIA fibres and a decreased proportion of type IIB fibres. In addition, the C/F ratio and cross-sectional area of fast-twitch fibres were normalized by superimposition of training on hypoxia. Both VO2max and ETE were significantly higher in trained H rats than in NAL, but these improvements were mainly related to the reduced body weight induced by hypoxia. These data suggest that the greater aerobic capacity and tolerance for prolonged exercise induced by chronic exposure to hypoxia can be mainly accounted for by the anorexic effects of hypoxia, although other factors (e.g. increase in oxygen carrying capacity induced by hypoxia acclimatization) may play a significant role in some circumstances (e.g. in sedentary rats).
1432-2013
14322013
Springer
shingle_catch_all_4 Abdelmalki, A.
Fimbel, S.
Mayet-Sornay, M. H.
Sempore, B.
Favier, R.
Aerobic capacity and skeletal muscle properties of normoxic and hypoxic rats in response to training
Key words Capillarization
Endurance time to exhaustion
Fast-and slow-twitch skeletal muscles
Fibre type distribution
Food restriction
Oxidative and glycolytic enzymes
Maximal oxygen uptake
Key words Capillarization
Endurance time to exhaustion
Fast-and slow-twitch skeletal muscles
Fibre type distribution
Food restriction
Oxidative and glycolytic enzymes
Maximal oxygen uptake
Abstract The aim of this study was to determine, in the rat, the effects of chronic exposure (7–9 weeks) to normobaric hypoxia (FIO2 = 0.13, equivalent to 3700 m altitude) on cardiac and skeletal muscle properties, on maximal oxygen uptake (VO2max), and endurance time to exhaustion (ETE). In addition, we evaluated the impact of endurance training (90 min of treadmill running per day, 5 days per week, for 9 weeks) on these parameters. The results were compared to normoxic rats fed ad libitum (NAL) and to normoxic pair-weight (NPW) animals in order to take into account the influence of hypoxia on growth rate. It was found that, in sedentary rats, hypoxia results in stunted growth, adrenal atrophy, a significant reduction of cross-sectional area of fast-twitch (type II) fibres, a reduced capillary-to-fibre ratio (C/F), and a reduced oxidative capacity (decreases in citrate synthase and 3-hydroxy-Acyl CoA dehydrogenase activities) of the plantaris muscle. These effects are mainly related to the anorexic effects of prolonged exposure to hypoxia. Nevertheless, hypoxic (H) rats displayed higher VO2max and ETE values when compared either to NAL or to NPW animals. Endurance training resulted, in all groups (H, NAL, NPW), in a significant change of the fibre type distribution of the plantaris which displayed an increased number of type IIA fibres and a decreased proportion of type IIB fibres. In addition, the C/F ratio and cross-sectional area of fast-twitch fibres were normalized by superimposition of training on hypoxia. Both VO2max and ETE were significantly higher in trained H rats than in NAL, but these improvements were mainly related to the reduced body weight induced by hypoxia. These data suggest that the greater aerobic capacity and tolerance for prolonged exercise induced by chronic exposure to hypoxia can be mainly accounted for by the anorexic effects of hypoxia, although other factors (e.g. increase in oxygen carrying capacity induced by hypoxia acclimatization) may play a significant role in some circumstances (e.g. in sedentary rats).
1432-2013
14322013
Springer
shingle_title_1 Aerobic capacity and skeletal muscle properties of normoxic and hypoxic rats in response to training
shingle_title_2 Aerobic capacity and skeletal muscle properties of normoxic and hypoxic rats in response to training
shingle_title_3 Aerobic capacity and skeletal muscle properties of normoxic and hypoxic rats in response to training
shingle_title_4 Aerobic capacity and skeletal muscle properties of normoxic and hypoxic rats in response to training
sigel_instance_filter dkfz
geomar
wilbert
ipn
albert
fhp
source_archive Springer Online Journal Archives 1860-2000
timestamp 2024-05-06T09:43:11.388Z
titel Aerobic capacity and skeletal muscle properties of normoxic and hypoxic rats in response to training
titel_suche Aerobic capacity and skeletal muscle properties of normoxic and hypoxic rats in response to training
topic WW-YZ
uid nat_lic_papers_NLM201007258