科研之友
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摘要
CO2 exposure elicits multiple changes in the acid-base balance and hematology of avian embryos, but the time-specific, dose-dependent effects of graded increases in extrinsic CO2 in a normoxic environment are poorly understood. Consequently, we exposed day 15 chicken embryos to 1, 3, 5, 6 or 10 % CO2 in 20 % O-2. We hypothesized that both the magnitude of hypercapnic respiratory acidosis and the resultant metabolic compensation within 24 h of exposure to %26lt; 10 % CO2 are proportional to ambient CO2 concentration ([CO2]). We also predicted that regulation of hematological respiratory variables is graded according to [CO2]. Time-course (2, 6 and 24 h) changes were determined for acid-base disturbances and hematological respiratory variables; hematocrit (Hct), red blood cell concentration ([RBC]), hemoglobin concentration, mean corpuscular volume (MCV) and other mean corpuscular indices. Both the decrease in uncompensated pH, which indicates uncompensated respiratory acidosis, and the compensatory pH increase, a sign of metabolic compensation, increased with [CO2]. The partial metabolic compensation across all CO2 gas mixtures was similar to 17, 46 and 53 % compensation at 2, 6 and 24 h, respectively. Hematological responses were nearly identical across the entire range of [CO2], with Hct decreasing across the time course of CO2 exposure due to a decrease in MCV from 2 to 24 h and a decrease in [RBC] at 24 h. Even though hematological regulation was not graded, chicken embryos were able to compensate and survive exposure to %26lt; 10 % CO2.
- 出版日期2014-7
