title: Regulatory processes of metabolic and respiratory acid-base disturbances in embryos.
abstract: First, preliminary experiments were designed in the 16-day-old individual chick embryo to elucidate the effect of electrolyte infusion and blood samplings on hemodilution, which might influence the acid-base balance. Three kinds of hemodilution were observed: 1) hemodilution caused by four repetitive samplings, which had no influence on acid-base balance; 2) hypervolumic hemodilution caused by infusion of solution whose volume equaled about 5-6% of total blood volume, which induced dilution acidosis; and 3) hypertonic hemodilution caused by hypertonic electrolyte infusion, which also induced dilution acidosis. The embryo recovered from the hypertonic dilution acidosis in 6 h after infusion, but it did not recover from hypervolumic acidosis. Second, the time course of changes in metabolic and respiratory acid-base disturbances was studied in the individual embryo. Metabolic acid-base disturbances made by hypertonic NaHCO3 infusion were restored to control state in 6 h. Respiratory acid-base disturbances were also regulated in terms of changes in plasma[HCO-3] and pH. The renal function and redistribution of HCO-3 may in part be responsible for the regulation.
mesh_terms: D000136:Acid-Base Equilibrium; D000818:Animals; D001639:Bicarbonates / Q000494:pharmacology; D001769:Blood; D001810:Blood Volume; D002642:Chick Embryo / Q000378:metabolism*; D006400:Hematocrit; D006438:Hemodilution; D006863:Hydrogen-Ion Concentration; D009994:Osmolar Concentration; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D001639:Bicarbonates; D012965:Sodium Chloride