scholarly journals Rat embryonic and foetal erythrocytes. High 2,3-bisphosphoglycerate and ATP and low oxygen affinity in vitro for nucleated embryonic cells

1980 ◽  
Vol 192 (1) ◽  
pp. 355-359 ◽  
Author(s):  
J G Gilman
Keyword(s):  
Oxygen Affinity ◽  
High Oxygen ◽  
Red Cells ◽  
Embryonic Cells ◽  
Low Oxygen ◽  
Foetal Life ◽  
High Oxygen Affinity ◽  
Low Oxygen Affinity

Embryonic nucleated red cells of the rat have high ATP and 2,3-bisphosphoglycerate and relatively low oxygen affinity. During foetal life they are replaced by large non-nucleated red cells with high ATP, low bisphosphoglycerate and high oxygen affinity. After birth, small non-nucleated red cells with high bisphosphoglycerate and low oxygen affinity rapidly predominate.

scholarly journals Methemoglobin reduction in red cells: effect of a high oxygen affinity hemoglobin

Blood ◽  
1980 ◽  
Vol 55 (1) ◽  
pp. 116-118
Author(s):  
F Taketa ◽  
KJ Matteson ◽  
JY Chen ◽  
JA Libnoch
Keyword(s):  
Oxygen Affinity ◽  
High Oxygen ◽  
Red Cells ◽  
Combined Effects ◽  
In Vitro System ◽  
Normal Human ◽  
High Oxygen Affinity ◽  
Heterozygous Carriers ◽  
Human Red Cells

Erythrocytes from heterozygous carriers of the high oxygen affinity mutant hemoglobin, Hb Wood, demonstrate lower rates of methemoglobin reduction than normal human red cells when incubated in the in vitro system of Beutler and Baluda. The rate of methemoglobin reduction in red cells from an individual who is heterozygous for both NADH- methoglobin reductase deficiency and Hb Wood shows the combined effects of the two mutations.

scholarly journals Methemoglobin reduction in red cells: effect of a high oxygen affinity hemoglobin

Blood ◽  
1980 ◽  
Vol 55 (1) ◽  
pp. 116-118 ◽  
Author(s):  
F Taketa ◽  
KJ Matteson ◽  
JY Chen ◽  
JA Libnoch
Keyword(s):  
Oxygen Affinity ◽  
High Oxygen ◽  
Red Cells ◽  
Combined Effects ◽  
In Vitro System ◽  
Normal Human ◽  
High Oxygen Affinity ◽  
Heterozygous Carriers ◽  
Human Red Cells

Abstract Erythrocytes from heterozygous carriers of the high oxygen affinity mutant hemoglobin, Hb Wood, demonstrate lower rates of methemoglobin reduction than normal human red cells when incubated in the in vitro system of Beutler and Baluda. The rate of methemoglobin reduction in red cells from an individual who is heterozygous for both NADH- methoglobin reductase deficiency and Hb Wood shows the combined effects of the two mutations.

scholarly journals Shifts in microbial transcription patterns prior to onset of Necrotizing enterocolitis may indicate low oxygen levels in the gut

2018 ◽  
Author(s):  
Yonatan Sher ◽  
Matthew R. Olm ◽  
Tali Raveh-Sadka ◽  
Christopher Brown ◽  
Ruth Sher ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Necrotizing Enterocolitis ◽  
Premature Infants ◽  
Oxygen Affinity ◽  
High Oxygen ◽  
Host Cells ◽  
Multiple Time ◽  
List Type ◽  
Low Oxygen ◽  
High Oxygen Affinity

SummaryPremature infants are at risk for developing necrotizing enterocolitis (NEC), an inflammatory disease that can progress to necrosis of gut tissue. Previous attempts have failed to identify any consistent predictor of NEC. We hypothesized that prior to the appearance of NEC symptoms, the gut microbiome shifts in its transcriptional profile. To test this hypothesis we integrated genome-resolved metagenomic and metatranscriptomic data from multiple time-points in the first month of life of four preterm infants, two of whom later developed NEC. Gut microbiomes of NEC infants showed increased transcription of high oxygen affinity cytochrome oxidases and lower transcription of genes to detoxify nitric oxide, an antimicrobial compound released by host cells. These results, and high transcription of H2 production genes, suggest low O2 conditions prior to NEC onset, and are consistent with hypoxic conditions in diseased gut tissue. The findings motivate further testing of transcript data as a predictor of NEC.HighlightsTranscription of high oxygen affinity microbial cytochrome oxidase may predict necrotizing enterocolitis (NEC) development.Lower transcription of microbial genes to detoxify nitric oxide (NO) may also predict NEC development.Higher transcription of H2 production genes by Escherichia sp. was found in the gut of premature infants that develop NEC.

Evolution of mammalian hemoglobin function

Blood ◽  
1981 ◽  
Vol 58 (2) ◽  
pp. 189-197 ◽  
Author(s):  
HF Bunn
Keyword(s):  
Oxygen Affinity ◽  
Red Cells ◽  
Red Cell ◽  
Low Oxygen ◽  
Wide Range ◽  
Blood Oxygen Affinity ◽  
Low Levels ◽  
Major Factors ◽  
2,3 Dpg ◽  
Low Oxygen Affinity

Throughout their evolution, mammalian hemoglobins have acquired a broad repertoire of functional properties well suited to the internal milieu of the red cell. Mammals display a wide range in whole blood oxygen affinity dependent on three major factors: the intrinsic oxygen affinity of the hemoglobin, the level of red cell 2,3-DPG, and the response of the hemoglobin to 2,3-DPG. The concentration of 2,3-DPG varies among groups of mammals. Those animals (cats and ruminants) that have very low levels of this intracellular mediator have hemoglobins of intrinsically low oxygen affinity that fail to respond to the addition of 2,3-DPG. Mammals that have adapted to various types of hypoxia tend to have increased oxygen affinity, primarily mediated through reduced levels of red cell 2,3-DPG. In contrast, mammals who are experimentally subjected to low oxygen tensions develop decreased oxygen affinity owing to increased red cell 2,3-DPG. Mammals employ one of three different mechanisms for the maintenance of higher oxygen affinity of fetal red cells, compared to maternal red cells. Many of these phenomena can be satisfactorily explained at the molecular level but their adaptational significance is less clear.

scholarly journals Evolution of mammalian hemoglobin function

Blood ◽  
1981 ◽  
Vol 58 (2) ◽  
pp. 189-197 ◽  
Author(s):  
HF Bunn
Keyword(s):  
Oxygen Affinity ◽  
Red Cells ◽  
Red Cell ◽  
Low Oxygen ◽  
Wide Range ◽  
Blood Oxygen Affinity ◽  
Low Levels ◽  
Major Factors ◽  
2,3 Dpg ◽  
Low Oxygen Affinity

Abstract Throughout their evolution, mammalian hemoglobins have acquired a broad repertoire of functional properties well suited to the internal milieu of the red cell. Mammals display a wide range in whole blood oxygen affinity dependent on three major factors: the intrinsic oxygen affinity of the hemoglobin, the level of red cell 2,3-DPG, and the response of the hemoglobin to 2,3-DPG. The concentration of 2,3-DPG varies among groups of mammals. Those animals (cats and ruminants) that have very low levels of this intracellular mediator have hemoglobins of intrinsically low oxygen affinity that fail to respond to the addition of 2,3-DPG. Mammals that have adapted to various types of hypoxia tend to have increased oxygen affinity, primarily mediated through reduced levels of red cell 2,3-DPG. In contrast, mammals who are experimentally subjected to low oxygen tensions develop decreased oxygen affinity owing to increased red cell 2,3-DPG. Mammals employ one of three different mechanisms for the maintenance of higher oxygen affinity of fetal red cells, compared to maternal red cells. Many of these phenomena can be satisfactorily explained at the molecular level but their adaptational significance is less clear.

scholarly journals Hb Toyoake: beta 142 (H20) Ala replaced by Pro. A new unstable hemoglobin with high oxygen affinity

Blood ◽  
1981 ◽  
Vol 57 (4) ◽  
pp. 697-704
Author(s):  
M Hirano ◽  
Y Ohba ◽  
K Imai ◽  
T Ino ◽  
Y Morishita ◽  
...  
Keyword(s):  
Oxygen Affinity ◽  
High Oxygen ◽  
Oxygen Binding ◽  
Subunit Dissociation ◽  
Japanese Male ◽  
Red Cell Survival ◽  
High Oxygen Affinity ◽  
Multiple Abnormalities ◽  
Unstable Hemoglobin

A new unstable hemoglobin with high oxygen affinity, Hb Toyoake: beta 142 (H20) Ala replaced by Pro, was found in Japanese male with a normal blood hemoglobin level, shortened red cell survival, and increased plasma erythropoietin. Hemoglobin studies showed heat and isopropanol instability, and an increased tendency to heme loss and to subunit dissociation. Electrophoresis of whole hemolysate showed inconstant abnormal bands with reduced mobilities due to progressive heme loss during the in vitro procedure. Isolated Hb Toyoake with normal heme content migrated slightly faster than HbA. Oxygen affinity of red cells was elevated with P50 of 17.0 mm Hg at pH 7.4 and 37 degrees C (normal 25.0 mm Hg). Studies on hemolysate implied that Hb Toyoake had an almost normal Bohr effect, a diminished cooperativity, and a reduced response to inositol hexaphosphate. These multiple abnormalities are associated with a substitution of Pro for beta 142 Ala, resulting in disruption of the H-helix and the adjacent C-terminal portion of beta chain, which contain residues crucial for normal oxygen binding.

scholarly journals Hb Toyoake: beta 142 (H20) Ala replaced by Pro. A new unstable hemoglobin with high oxygen affinity

Blood ◽  
1981 ◽  
Vol 57 (4) ◽  
pp. 697-704 ◽  
Author(s):  
M Hirano ◽  
Y Ohba ◽  
K Imai ◽  
T Ino ◽  
Y Morishita ◽  
...  
Keyword(s):  
Oxygen Affinity ◽  
High Oxygen ◽  
Oxygen Binding ◽  
Subunit Dissociation ◽  
Japanese Male ◽  
Red Cell Survival ◽  
High Oxygen Affinity ◽  
Multiple Abnormalities ◽  
Unstable Hemoglobin

Abstract A new unstable hemoglobin with high oxygen affinity, Hb Toyoake: beta 142 (H20) Ala replaced by Pro, was found in Japanese male with a normal blood hemoglobin level, shortened red cell survival, and increased plasma erythropoietin. Hemoglobin studies showed heat and isopropanol instability, and an increased tendency to heme loss and to subunit dissociation. Electrophoresis of whole hemolysate showed inconstant abnormal bands with reduced mobilities due to progressive heme loss during the in vitro procedure. Isolated Hb Toyoake with normal heme content migrated slightly faster than HbA. Oxygen affinity of red cells was elevated with P50 of 17.0 mm Hg at pH 7.4 and 37 degrees C (normal 25.0 mm Hg). Studies on hemolysate implied that Hb Toyoake had an almost normal Bohr effect, a diminished cooperativity, and a reduced response to inositol hexaphosphate. These multiple abnormalities are associated with a substitution of Pro for beta 142 Ala, resulting in disruption of the H-helix and the adjacent C-terminal portion of beta chain, which contain residues crucial for normal oxygen binding.

scholarly journals A Transgenic Mouse Model of Hemoglobin S Antilles Disease

Blood ◽  
1997 ◽  
Vol 89 (11) ◽  
pp. 4204-4212 ◽  
Author(s):  
R.A. Popp ◽  
D.M. Popp ◽  
S.G. Shinpock ◽  
M.Y. Yang ◽  
J.G. Mural ◽  
...  
Keyword(s):  
Sickle Cell ◽  
Experimental Studies ◽  
Oxygen Affinity ◽  
High Oxygen ◽  
Lower Solubility ◽  
Lower Oxygen ◽  
Hb S ◽  
High Oxygen Affinity

Abstract Hemoglobin (Hb) S Antilles is a naturally occurring form of sickling human Hb but causes a more severe phenotype than Hb S. Two homozygous viable Hb S Antilles transgene insertions from Tg58Ru and Tg98Ru mice were bred into MHOAH mice that express high oxygen affinity (P50 ∼24.5 mm Hg) rather than normal (P50 ∼40 mm Hg) mouse Hbs. The rationale was that the high oxygen affinity MHOAH Hb, the lower oxygen affinity of Hb S Antilles than Hb S (P50 ∼40 v 26.5 mm Hg), and the lower solubility of deoxygenated Hb S Antilles than Hb S (∼11 v 18 g/dL) would favor deoxygenation and polymerization of human Hb S Antilles in MHOAH mouse red blood cells (RBCs). The Tg58 × Tg98 mice produced have a high and balanced expression (∼50% each) of hα and hβS Antilles globins, 25% to 35% of their RBCs are misshapen in vivo, and in vitro deoxygenation of their blood induces 30% to 50% of the RBCs to form classical looking, elongated sickle cells with pointed ends. Tg58 × Tg98 mice exhibit reticulocytosis, an elevated white blood cell count and lung and kidney pathology commonly found in sickle cell patients, which should make these mice useful for experimental studies on possible therapeutic intervention of sickle cell disease.

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