کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9152484 1167450 2005 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Changes in respiratory control after 5 days at altitude
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی فیزیولوژی
پیش نمایش صفحه اول مقاله
Changes in respiratory control after 5 days at altitude
چکیده انگلیسی
These experiments examined changes in the chemoreflex control of breathing and acid-base balance after 5 days at altitude (3480 m) in six healthy males. The partial pressures of carbon dioxide (PCO2) at which ventilation increased during isoxic hypoxic and hyperoxic modified rebreathing tests at sea level fell significantly at altitude by mean ± S.E.M. of 12.8 ± 2.51 mmHg and 9.5 ± 1.77 mmHg, respectively, but response slopes above threshold were unchanged. Altitude exposure produced a respiratory alkalosis evidenced by a decrease in mean resting end-tidal PCO2 from 41 ± 0.84 mmHg at sea level to 32 ± 2.04 mmHg at altitude, but pH did not increase significantly from its sea level value. Blood samples were analyzed to discover acid-base changes, using a modification of the equations for acid-base balance proposed by [Stewart, P.A., 1983. Modern quantitative acid-base chemistry. Can. J. Physiol. Pharmacol. 61, 1444-1461]. While strong ion difference at altitude was not significantly different from its sea level value, albumin concentration was increased significantly from 38.6 ± 0.30 g L−1 to 49.8 ± 0.76 g L−1. We suggest that the respiratory alkalosis was produced by a fall in the chemoreflex threshold and pH was corrected by an elevation in the concentration of weakly dissociated protein anions.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Respiratory Physiology & Neurobiology - Volume 145, Issue 1, January 2005, Pages 41-52
نویسندگان
, , , , ,