کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2847280 | 1167347 | 2013 | 9 صفحه PDF | دانلود رایگان |
In day 15 chicken embryos, we determined the time course responses of acid–base balance and hematological respiratory variables during 24 h exposure to 15, 20, 40 or 90% O2, in the presence of 5% CO2. Hypercapnic respiratory acidosis was initially (2 h) only slightly (∼20%) compensated by metabolic alkalosis in normoxic/hyperoxic embryos. After 6 h, respiratory acidosis was partially (∼40–50%) compensated not only in normoxic/hyperoxic embryos, but also in hypoxic embryos. However, partial metabolic compensation in 15% O2 could not be preserved after 24 h. Preservation of metabolic compensation required oxygen concentration ([O2]) above 20%, but the magnitude of partial metabolic compensation was unrelated to [O2]. Hematocrit (Hct), together with mean corpuscular volume (MCV), markedly increased in hypercapnic hypoxia, and was maintained at 24 h due to a subsequent increase in red blood cell concentration ([RBC]). In contrast, Hct, together with MCV, decreased in hypercapnic normoxia/hyperoxia accompanied by a subsequent decrease in [RBC] at 24 h. Regulation of variables takes place similarly irrespective of environmental [O2] above 20%, matching acid–base regulation.
► We study acid–base regulation and hematology under gas challenges in chick embryos.
► Gas challenges include hypercapnia (5% CO2) hypoxia, normoxia and hyperoxia (15, 20, 40 and 90% O2).
► Time course responses to respiratory acidosis vary with oxygen concentration under hypercapnia.
► Metabolic compensation is not maintained 24 h after exposure to hypercapnic hypoxia.
► The mechanism behind hematocrit regulation changes with gas exposure time.
Journal: Respiratory Physiology & Neurobiology - Volume 185, Issue 2, 15 January 2013, Pages 272–280