title: Dynamics of acid-base and hematological regulation in day 15 chicken embryos (Gallus gallus domesticus) exposed to graded hypercapnia and hypoxia.
abstract: Most experiments examining acid-base regulation of chicken embryos have employed static, single time point measurements rather than dynamic, multiple time point measurements that might reveal additional components of developing acid-base regulation. Thus, we studied blood acid-base balance and hematology of day 15 chicken embryos under 24h exposure to graded hypercapnia (1%-7% CO2) accompanied by graded hypoxia (20% O2down to 13% O2). Across all hypercapnic/hypoxic environments, respiratory acidosis occurred 2h after exposure in proportion to the magnitude of hypercapnia. An additional metabolic alkalosis occurred in ≥16% O2, and metabolic acidosis in ≤14% O2. As exposure progressed, compensatory metabolic alkalosis occurred in all groups at 6h, but partial metabolic compensation could not be preserved as hypoxia increased (≤18% O2). Across all hypercapnic/hypoxic groups, hematocrit, mean corpuscular volume and red blood cell concentration significantly increased by 24h, most likely due to hypoxia rather than hypercapnia. Overall, day 15 chicken embryos cannot maintain even partial compensation in their acid-base physiology after 24h exposure to hypercapnic/hypoxic environments of ≥5% CO2+≤15% O2.
authors.affiliation: Department of Biological Sciences, California State University San Marcos, 333 S. Twin Oaks Valley Road, San Marcos, CA 92096, USA. Electronic address: cmueller@csusm.edu.
authors.forename: Casey A
authors.initials: CA
authors.lastname: Mueller
authors.affiliation: Developmental Integrative Biology, Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX 76203, USA.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tazawa
authors.affiliation: Developmental Integrative Biology, Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX 76203, USA.
authors.forename: Warren W
authors.initials: WW
authors.lastname: Burggren
mesh_terms: D000136:Acid-Base Equilibrium / Q000502:physiology*; D000142:Acidosis, Respiratory / Q000209:etiology*; D000367:Age Factors; D000818:Animals; D002245:Carbon Dioxide / Q000494:pharmacology; D002642:Chick Embryo; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000473:pathology; D006400:Hematocrit; D006935:Hypercapnia / Q000378:metabolism*; D000860:Hypoxia / Q000378:metabolism*; D010100:Oxygen / Q000494:pharmacology
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen
keywords: Acid-base disturbances; Chicken embryos; Hematology; Hypercapnia; Hypoxia; Metabolic compensation