M Marlinge1,2, D Vairo1,2, R Guieu3,4, F Joulia1,5, A Bertaud1, C Vernet2, M Chefrour2, L Bruzzese1, M C Chaptal1, G Mottola1,2, A Boussuges1,6, J J Risso6, M Blot-Chabaud1, M Coulange1,5. 1. C2VN, INSERM 1263, INRAE 1260, Faculty of Pharmacy, Aix Marseille University, Bvd J Moulin 13005, Marseille, France. 2. Laboratory of Biochemistry, Timone Hospital, Marseille, France. 3. C2VN, INSERM 1263, INRAE 1260, Faculty of Pharmacy, Aix Marseille University, Bvd J Moulin 13005, Marseille, France. guieu.regis@orange.fr. 4. Laboratory of Biochemistry, Timone Hospital, Marseille, France. guieu.regis@orange.fr. 5. UFR STAPS, Toulon University, Toulon, France. 6. ERRSO: Institute of Biomedical Research of the French Army (IRBA), Toulon, France.
Abstract
PURPOSE: Long static or intense dynamic apnoea-like high-altitude exposure is inducing hypoxia. Adenosine is known to participate to the adaptive response to hypoxia leading to the control of heart rate, blood pressure and vasodilation. Extracellular adenosine level is controlled through the equilibrative nucleoside transporter 1 (ENT-1) and the enzyme adenosine deaminase (ADA). The aim of this study was to determine the control of adenosine blood level (ABL) via ENT-1 and ADA during apnoea-induced hypoxia in elite freedivers was similar to high-altitude adaptation. METHODS: Ten freediver champions and ten controls were studied. Biological (e.g. ENT-1, ADA, ABL, PaO2, PaCO2 and pH) and cardiovascular (e.g. heart rate, arterial pressure) parameters were measured at rest and after a submaximal dry static apnoea. RESULTS: In freedivers, ABL was higher than in control participants in basal condition and increased more in response to apnoea. Also, freedivers showed an ADA increased in response to apnoea. Finally, ENT-1 level and function were reduced for the free divers. CONCLUSION: Our results suggest in freedivers the presence of an adaptive mechanism similar to the one observed in human exposed to chronic hypoxia induced by high-altitude environment.
PURPOSE: Long static or intense dynamic apnoea-like high-altitude exposure is inducing hypoxia. Adenosine is known to participate to the adaptive response to hypoxia leading to the control of heart rate, blood pressure and vasodilation. Extracellular adenosine level is controlled through the equilibrative nucleoside transporter 1 (ENT-1) and the enzyme adenosine deaminase (ADA). The aim of this study was to determine the control of adenosine blood level (ABL) via ENT-1 and ADA during apnoea-induced hypoxia in elite freedivers was similar to high-altitude adaptation. METHODS: Ten freediver champions and ten controls were studied. Biological (e.g. ENT-1, ADA, ABL, PaO2, PaCO2 and pH) and cardiovascular (e.g. heart rate, arterial pressure) parameters were measured at rest and after a submaximal dry static apnoea. RESULTS: In freedivers, ABL was higher than in control participants in basal condition and increased more in response to apnoea. Also, freedivers showed an ADA increased in response to apnoea. Finally, ENT-1 level and function were reduced for the free divers. CONCLUSION: Our results suggest in freedivers the presence of an adaptive mechanism similar to the one observed in human exposed to chronic hypoxia induced by high-altitude environment.
Authors: Paola Casanello; Alberto Torres; Felipe Sanhueza; Marcelo González; Marcelo Farías; Victoria Gallardo; Marçal Pastor-Anglada; Rody San Martín; Luis Sobrevia Journal: Circ Res Date: 2005-06-02 Impact factor: 17.367
Authors: Stephen A Baldwin; Paul R Beal; Sylvia Y M Yao; Anne E King; Carol E Cass; James D Young Journal: Pflugers Arch Date: 2003-06-28 Impact factor: 3.657