title: Studies on avian erythrocyte metabolism. XIV. Effect of CO2 and pH on P50 in the chicken.
abstract: The O2 affinity (P50) of erythrocyte suspensions from 18-day chick embryos, from 2-, 5-, 8-, and 14-day chicks, and from mature chickens decreased with increasing concentrations of either CO2 or H+, particularly at a pH near 7.4 and at 37 degrees C. A greater effect on delta P50's was observed from increasing H+ concentration from pH 8.0 to 6.8 in cell suspensions from 18-day embryos (28.8 Torr at 0% CO2) and adult chickens (55.1 Torr at 0% CO2) than from increases in CO2 concentration at any given pH. The Bohr effect (delta log P50/delta pH) in the absence of CO2 was -0.508 and -0.479 for cell suspensions from 18-day chick embryos and adult birds, respectively. The specific effect of CO2 on the Bohr effect, regardless of the CO2 concentration, indicates that the delta P50/0.1 pH is approximately 1.35 and 2.45 Torr for the embryo and adult chicken blood. These results indicate that increasing H+ and CO2 concentrations markedly affect the P50 of chicken blood and that even subtle changes in either could play a significant role physiologically in regulating blood P50 in birds.
authors.forename: R
authors.initials: R
authors.lastname: Isaacks
authors.forename: P
authors.initials: P
authors.lastname: Goldman
authors.forename: C
authors.initials: C
authors.lastname: Kim
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000494:pharmacology*; D002642:Chick Embryo; D002645:Chickens / Q000097:blood*; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010101:Oxygen Consumption; D010108:Oxyhemoglobins / Q000378:metabolism
chemical_list: D010108:Oxyhemoglobins; D002245:Carbon Dioxide