title: Brain tissue hypoxia and oxidative stress induced by obstructive apneas is different in young and aged rats.
abstract: OBJECTIVE
  To test the hypotheses that brain oxygen partial pressure (PtO2) in response to obstructive apneas changes with age and that it might lead to different levels of cerebral tissue oxidative stress.
  
  
  METHODS
  Prospective controlled animal study.
  
  
  METHODS
  University laboratory.
  
  
  METHODS
  Sixty-four male Wistar rats: 32 young (3 mo old) and 32 aged (18 mo).
  
  
  METHODS
  Protocol 1: Twenty-four animals were subjected to obstructive apneas (50 apneas/h, lasting 15 sec each) or to sham procedure for 50 min. Protocol 2: Forty rats were subjected to obstructive apneas or sham procedure for 4 h.
  
  
  RESULTS
  Protocol 1: Real-time PtO2 measurements were performed using a fast-response oxygen microelectrode. During successive apneas cerebral cortex PtO2 presented a different pattern in the two age groups; there was a fast increase in young rats, whereas it remained without significant changes between the beginning and the end of the protocol in the aged group. Protocol 2: Brain oxidative stress assessed by lipid peroxidation increased after apneas in young rats (1.34 ± 0.17 nmol/mg of protein) compared to old ones (0.63 ± 0.03 nmol/mg), where a higher expression of antioxidant enzymes was observed.
  
  
  CONCLUSIONS
  The results suggest that brain oxidative stress in aged rats is lower than in young rats in response to recurrent apneas, mimicking obstructive sleep apnea. This could be due to the different PtO2 response observed between age groups and the increased antioxidant expression in aged rats.
  
  
  BACKGROUND
  Dalmases M, Torres M, Márquez-Kisinousky L, Almendros I, Planas AM, Embid C, Martínez-Garcia MA, Navajas D, Farré R, Montserrat JM. Brain tissue hypoxia and oxidative stress induced by obstructive apneas is different in young and aged rats.
authors: Laboratori de la Son, Pneumologia, Hospital Clinic-Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain ; CIBER Enfermedades Respiratorias, Bunyola, Spain.
authors: Mireia
authors: M
authors: Dalmases
authors: Laboratori de la Son, Pneumologia, Hospital Clinic-Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain ; CIBER Enfermedades Respiratorias, Bunyola, Spain.
authors: Marta
authors: M
authors: Torres
authors: Departament d'Isquemia cerebral y neurodegeneració, IIBB-CSIC-IDIBAPS, Barcelona, Spain.
authors: Leonardo
authors: L
authors: Márquez-Kisinousky
authors: Laboratori de la Son, Pneumologia, Hospital Clinic-Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain ; CIBER Enfermedades Respiratorias, Bunyola, Spain.
authors: Isaac
authors: I
authors: Almendros
authors: Departament d'Isquemia cerebral y neurodegeneració, IIBB-CSIC-IDIBAPS, Barcelona, Spain.
authors: Anna M
authors: AM
authors: Planas
authors: Laboratori de la Son, Pneumologia, Hospital Clinic-Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain ; CIBER Enfermedades Respiratorias, Bunyola, Spain.
authors: Cristina
authors: C
authors: Embid
authors: Servicio de Neumología, Hospital Universitario y Politécnico La Fe, Valencia, Spain.
authors: Miguel Ángel
authors: MÁ
authors: Martínez-Garcia
authors: CIBER Enfermedades Respiratorias, Bunyola, Spain ; Unitat de Biofisica i Bioenginyeria, Facultat de Medicina, Universitat de Barcelona-IDIBAPS, Barcelona, Spain ; Institut de Bioenginyeria de Catalunya, Barcelona, Spain.
authors: Daniel
authors: D
authors: Navajas
authors: CIBER Enfermedades Respiratorias, Bunyola, Spain ; Unitat de Biofisica i Bioenginyeria, Facultat de Medicina, Universitat de Barcelona-IDIBAPS, Barcelona, Spain.
authors: Ramon
authors: R
authors: Farré
authors: Laboratori de la Son, Pneumologia, Hospital Clinic-Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain ; CIBER Enfermedades Respiratorias, Bunyola, Spain.
authors: Josep Maria
authors: JM
authors: Montserrat
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000378:metabolism* / Q000503:physiopathology; D002540:Cerebral Cortex / Q000378:metabolism / Q000503:physiopathology; D005978:Glutathione / Q000378:metabolism; D002534:Hypoxia, Brain / Q000378:metabolism* / Q000503:physiopathology; D015227:Lipid Peroxidation; D008297:Male; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism*; D010313:Partial Pressure; D011446:Prospective Studies; D051381:Rats; D017208:Rats, Wistar; D020181:Sleep Apnea, Obstructive / Q000378:metabolism* / Q000503:physiopathology*
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D005978:Glutathione; D010100:Oxygen
keywords: aging; animal model; obstructive apnea; oxidative stress; tissue oxygenation