tailieunhanh - Báo cáo y học: "Changes in oxygen partial pressure of brain tissue in an animal model of obstructive apnea"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học 'Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài:"Changes in oxygen partial pressure of brain tissue in an animal model of obstructive apnea. | Almendros et al. Respiratory Research 2010 11 3 http content 11 1 3 RESPIRATORY RESEARCH RESEARCH Open Access Changes in oxygen partial pressure of brain tissue in an animal model of obstructive apnea I z Al m I r 1 I IV ỉ IV I r ntmmt 1 2 IV ỉ I z . u- V-JS r 2 f U r f- r I r f r -7 2 I - -7 1 3 í I l l- v - í- r 1 4 5 D Z S. c s r r r 1 4 Isaac Almendros Josep M Montserrat Marta Torres Constancio Gonzalez Daniel Navajas Ramon rarre Abstract Background Cognitive impairment is one of the main consequences of obstructive sleep apnea OSA and is usually attributed in part to the oxidative stress caused by intermittent hypoxia in cerebral tissues. The presence of oxygen-reactive species in the brain tissue should be produced by the deoxygenation-reoxygenation cycles which occur at tissue level during recurrent apneic events. However how changes in arterial blood oxygen saturation SpO2 during repetitive apneas translate into oxygen partial pressure PtO2 in brain tissue has not been studied. The objective of this study was to assess whether brain tissue is partially protected from intermittently occurring interruption of O2 supply during recurrent swings in arterial SpO2 in an animal model of OSA. Methods Twenty-four male Sprague-Dawley rats 300-350 g were used. Sixteen rats were anesthetized and non-invasively subjected to recurrent obstructive apneas 60 apneas h 15 s each for 1 h. A control group of 8 rats was instrumented but not subjected to obstructive apneas. PtO2 in the cerebral cortex was measured using a fastresponse oxygen microelectrode. SpO2 was measured by pulse oximetry. The time dependence of arterial SpO2 and brain tissue PtO2 was carried out by Friedman repeated measures ANOVA. Results Arterial SpO2 showed a stable periodic pattern no significant changes in maximum m SE and minimum values . By contrast brain tissue PtO2 exhibited a different pattern from that of arterial SpO2. The minimum cerebral cortex PtO2 .