title: Acute regulation of hematocrit and acid-base balance in chicken embryos in response to severe intrinsic hypercapnic hypoxia.
abstract: The regulation of blood acid-base balance and hematology in day 15 chicken embryos in response to partial water submersion (with egg's air cell in air) and complete submersion producing severe intrinsic hypercapnic hypoxia and recovery in air was studied. The acid-base disturbance during submersion was characterized by initial rapid respiratory changes and then superseded by metabolic processes, resulting in a large progressive hysteresis. Throughout submersion and recovery, blood lactate concentration changed swiftly along with the changes in bicarbonate concentration ([HCO3(-)]), indicating that anaerobic glycolysis determined overall acid-base disturbances. Both partial and complete submersion produced large, rapid increases in hematocrit through proportional increases in mean corpuscular volume and red blood cell concentration. Death ensued once the internal pool of O2 was exhausted and/or the acid-base disturbance became too severe for survival (i.e., [HCO3(-)]a<∼10mmolL(-1)). However, embryos recovered from acid-base and hematological disturbances within 120min recovery in air after short bouts of complete (20min) or partial (60min) submersion, suggesting that shorter severe intrinsic hypercapnic hypoxia does not compromise viability of embryos.
authors: Developmental and Integrative Biology, Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX 76203, USA.
authors: Sarah J
authors: SJ
authors: Andrewartha
authors: Developmental and Integrative Biology, Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX 76203, USA.
authors: Hiroshi
authors: H
authors: Tazawa
authors: Developmental and Integrative Biology, Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX 76203, USA. Electronic address: burggren@unt.edu.
authors: Warren W
authors: WW
authors: Burggren
mesh_terms: D000136:Acid-Base Equilibrium; D000137:Acid-Base Imbalance / Q000503:physiopathology*; D000818:Animals; D002642:Chick Embryo; D004909:Erythrocyte Indices; D004912:Erythrocytes / Q000473:pathology / Q000502:physiology; D006400:Hematocrit; D006935:Hypercapnia / Q000473:pathology / Q000503:physiopathology*; D000860:Hypoxia / Q000473:pathology / Q000503:physiopathology*; D007101:Immersion; D019344:Lactic Acid / Q000097:blood; D009994:Osmolar Concentration; D010101:Oxygen Consumption; D016019:Survival Analysis; D013997:Time Factors
chemical_list: D019344:Lactic Acid
keywords: Acid–base balance; Chicken embryo; Hct; Lactate; Severe intrinsic hypoxia; Water submersion