A fetal-maternal shift in the oxygen equilibrium of hemoglobin from the viviparous caecilian,Typhlonectes compressicauda

Maternal-Fetal Trophic and Respiratory Relationships in Viviparous Ectothermic Vertebrates

“…This tallies with a significantly higher embryonic blood oxygen affinity (P 50 = 11 compared to 22 mmHg in the maternal blood) (Toews and Macintyre 1977;Garlick et al 1979). That the difference is mediated entirely by organic phosphates follows from identical electrophoretic patterns and intrinsic Hb-oxygen affinities in both stages, and a threefold greater concentration in the adults of NTP, which consists of about 90% ATP and 100/0 GTP (Garlick et al 1979). ATP drastically increases the Bohr factor of the stripped Hb (Lllog P 501 LlpH falling from 0 to -0.45), indicating the occurrence of a larger Bohr effect in the adult blood that will increase the transfer potential under lower pH.…”

Maternal-Fetal Trophic and Respiratory Relationships in Viviparous Ectothermic Vertebrates

“…This tallies with a significantly higher embryonic blood oxygen affinity (P 50 = 11 compared to 22 mmHg in the maternal blood) (Toews and Macintyre 1977;Garlick et al 1979). That the difference is mediated entirely by organic phosphates follows from identical electrophoretic patterns and intrinsic Hb-oxygen affinities in both stages, and a threefold greater concentration in the adults of NTP, which consists of about 90% ATP and 100/0 GTP (Garlick et al 1979). ATP drastically increases the Bohr factor of the stripped Hb (Lllog P 501 LlpH falling from 0 to -0.45), indicating the occurrence of a larger Bohr effect in the adult blood that will increase the transfer potential under lower pH.…”

Studies on the linkage between spin equilibria and protein structure in carp ferric hemoglobin

“…After incubation at 4°C for 30 min this solution was passed through a G-25 coarse Sephadex column equilibrated with 1 mM Tris, pH 8. The eluted methemoglobin solution was then passed over a Dintzis deionizing column [13] to remove organic phosphates as well as all other small ions. The resulting solution was concentrated in an Amicon pressure filtration apparatus to roughly 15 mM in heme equivalents.…”

Fetal adaptations for viviparity in amphibians

“…Toews and MacIntyre () found that advanced fetuses have a much higher O 2 saturation than maternal females, and suggest that the high hemoglogin saturation in fetuses would, therefore, be achieved even though maternal saturation is moderate, as a feature of maternal‐fetal gas exchange. Garlick et al () reported similarly that Typhlonectes compressicauda has a shift in equilibrium and kinetics of oxygen binding by blood and hemoglobin, with the oxygen affinity of fetal blood higher than that of adult blood. Fetal and adult hemoglobins appear to be biochemically identical.…”

Maternal-Fetal Trophic and Respiratory Relationships in Viviparous Ectothermic Vertebrates

“…This tallies with a significantly higher embryonic blood oxygen affinity (P 50 = 11 compared to 22 mmHg in the maternal blood) (Toews and Macintyre 1977;Garlick et al 1979). That the difference is mediated entirely by organic phosphates follows from identical electrophoretic patterns and intrinsic Hb-oxygen affinities in both stages, and a threefold greater concentration in the adults of NTP, which consists of about 90% ATP and 100/0 GTP (Garlick et al 1979). ATP drastically increases the Bohr factor of the stripped Hb (Lllog P 501 LlpH falling from 0 to -0.45), indicating the occurrence of a larger Bohr effect in the adult blood that will increase the transfer potential under lower pH.…”

Studies on the linkage between spin equilibria and protein structure in carp ferric hemoglobin

“…After incubation at 4°C for 30 min this solution was passed through a G-25 coarse Sephadex column equilibrated with 1 mM Tris, pH 8. The eluted methemoglobin solution was then passed over a Dintzis deionizing column [13] to remove organic phosphates as well as all other small ions. The resulting solution was concentrated in an Amicon pressure filtration apparatus to roughly 15 mM in heme equivalents.…”

Fetal adaptations for viviparity in amphibians

“…Toews and MacIntyre () found that advanced fetuses have a much higher O 2 saturation than maternal females, and suggest that the high hemoglogin saturation in fetuses would, therefore, be achieved even though maternal saturation is moderate, as a feature of maternal‐fetal gas exchange. Garlick et al () reported similarly that Typhlonectes compressicauda has a shift in equilibrium and kinetics of oxygen binding by blood and hemoglobin, with the oxygen affinity of fetal blood higher than that of adult blood. Fetal and adult hemoglobins appear to be biochemically identical.…”

Maternal-Fetal Trophic and Respiratory Relationships in Viviparous Ectothermic Vertebrates

“…This tallies with a significantly higher embryonic blood oxygen affinity (P 50 = 11 compared to 22 mmHg in the maternal blood) (Toews and Macintyre 1977;Garlick et al 1979). That the difference is mediated entirely by organic phosphates follows from identical electrophoretic patterns and intrinsic Hb-oxygen affinities in both stages, and a threefold greater concentration in the adults of NTP, which consists of about 90% ATP and 100/0 GTP (Garlick et al 1979). ATP drastically increases the Bohr factor of the stripped Hb (Lllog P 501 LlpH falling from 0 to -0.45), indicating the occurrence of a larger Bohr effect in the adult blood that will increase the transfer potential under lower pH.…”

Studies on the linkage between spin equilibria and protein structure in carp ferric hemoglobin

“…After incubation at 4°C for 30 min this solution was passed through a G-25 coarse Sephadex column equilibrated with 1 mM Tris, pH 8. The eluted methemoglobin solution was then passed over a Dintzis deionizing column [13] to remove organic phosphates as well as all other small ions. The resulting solution was concentrated in an Amicon pressure filtration apparatus to roughly 15 mM in heme equivalents.…”

Fetal adaptations for viviparity in amphibians

“…Toews and MacIntyre () found that advanced fetuses have a much higher O 2 saturation than maternal females, and suggest that the high hemoglogin saturation in fetuses would, therefore, be achieved even though maternal saturation is moderate, as a feature of maternal‐fetal gas exchange. Garlick et al () reported similarly that Typhlonectes compressicauda has a shift in equilibrium and kinetics of oxygen binding by blood and hemoglobin, with the oxygen affinity of fetal blood higher than that of adult blood. Fetal and adult hemoglobins appear to be biochemically identical.…”