The control of oxygen affinity in the three human embryonic haemoglobins by respiration linked metabolites

Hofmann, Oliver; Brittain, Thomas; Wells, R. M. G.

doi:10.1080/15216549700202961

Cited by 2 publications

(1 citation statement)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…properties that may compensate for the weak development of anatomical structures for gas exchange). 22 These Hb have ␣-like -chains assembling into 2⑀2-tetramers, which are gradually replaced by ones of lower affinity and greater cooperativity and Bohr effects as the gas exchange structures develop and placental barriers are reduced. 16,23 While the transfer of oxygen across a declining PO2 gradient from maternal to embryonic tissues is thus explained, recent findings on the 'free-living' embryos of marsupials are puzzling and show that the wallaby embryonic Hb has an extremely low affinity for oxygen.…”

Section: Regulation Of Haemoglobin Function During Ontogenymentioning

confidence: 99%

Evolution of Haemoglobin Function: Molecular Adaptations to Environment

Wells

1999

Clin Exp Pharma Physio

View full text Add to dashboard Cite

SUMMARY1. Nearly 1000 mutations have been described for human haemoglobin (Hb), many of which result in subtle changes to the oxygen transport system. Similar changes have occurred over the course of animal evolution resulting in a diversity of functional attributes which appear to correlate the availability of oxygen in the environment with metabolic demand.2. At an early stage in evolution, worm-like animals had large, polymeric aggregations of Hb subunits circulating through primitive circulatory systems and some possessed monomeric Hb in blood cells functioning as an oxygen store.3. The circulating vertebrate red blood cell provides an environment allowing haem units to interact among themselves and with various organic phosphates to allow a responsive and highly regulated system of gas transport. During metazoan evolution the burden of physiological regulation has shifted from the cells to organ systems, as endothermy and aerial breathing permit a relatively constant environment.4. An understanding of the adaptive possibilities of Hb has helped us to understand the ontogeny of oxygen transport and to interpret recently described functional properties of human embryonic haemoglobins.

show abstract

Section: Regulation Of Haemoglobin Function During Ontogenymentioning

confidence: 99%