Beyond just hemoglobin: Red blood cell potentiation of hemoglobin-oxygen unloading in fish.

  title={Beyond just hemoglobin: Red blood cell potentiation of hemoglobin-oxygen unloading in fish.},
  author={Colin J Brauner and Till S. Harter},
  journal={Journal of applied physiology},
  volume={123 4},
Teleosts comprise 95% of fish species, almost one-half of all vertebrate species, and represent one of the most successful adaptive radiation events among vertebrates. This is thought to be in part because of their unique oxygen (O2) transport system. In salmonids, recent in vitro and in vivo studies indicate that hemoglobin-oxygen (Hb-O2) unloading to tissues may be doubled or even tripled under some conditions without changes in perfusion. This is accomplished through the short circuiting of… Expand
Time course of red blood cell intracellular pH recovery following short-circuiting in relation to venous transit times in rainbow trout, Oncorhynchus mykiss.
Teleosts have evolved a system that greatly enhances O2 unloading from pH-sensitive Hb at the tissues, while protecting O2 loading at the gills; the resulting increase in O2 transport per unit of blood flow may enable the tremendous athletic ability of salmonids. Expand
Red blood cell carbonic anhydrase mediates oxygen delivery via the Root effect in red drum
Biochemical and metabolic evidence supports a role for red blood cell carbonic anhydrase activity in dictating the rate of O2 delivery in red drum (Sciaenops ocellatus). Expand
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The data demonstrated that the cAMP/PKA signaling pathway and NO are involved in the regulation of crucian carp RBC osmotic fragility, but not in RVD response. Expand
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The functional significance of plasma-accessible carbonic anhydrase for cardiovascular oxygen transport in teleosts
........................................................................................................................................ iii Lay SummaryExpand
Translation in Progress: Hypoxia 2017.
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A unique mode of tissue oxygenation and the adaptive radiation of teleost fishes
It is suggested that this unique mode of tissue O2 transfer evolved in the Triassic/Jurassic Period, when O2 levels were low, ultimately giving rise to the most extensive adaptive radiation of extant vertebrates, the teleost fishes. Expand
Root Effect Haemoglobins in Fish May Greatly Enhance General Oxygen Delivery Relative to Other Vertebrates
These characteristics may be central to performance of athletic fish species such as salmonids, but may indicate that general tissue oxygen delivery may have been the incipient function of Root effect Hbs in fish, a trait strongly associated with the adaptive radiation of teleosts. Expand
Plasma-accessible carbonic anhydrase at the tissue of a teleost fish may greatly enhance oxygen delivery: in vitro evidence in rainbow trout, Oncorhynchus mykiss
If plasma-accessible CA-mediated short-circuiting is operational in vivo, the combined Bohr-Root effect system unique to teleost fishes could markedly enhance tissue O2 delivery far in excess of that in vertebrates possessing a Bohr effect alone and may lead to insights about the early evolution of the Root effect. Expand
Root Effect Hemoglobin May Have Evolved to Enhance General Tissue Oxygen Delivery
It is reported that when rainbow trout are exposed to elevated water carbon dioxide, red muscle partial pressure of oxygen (PO2) increases by 65%—evidence that Root hemoglobins enhance general tissue O2 delivery during acidotic stress, and argues that CA activity in muscle capillaries short-circuits red blood cell (RBC) pH regulation. Expand
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Blood oxygen transport in stressed striped bass (Morone saxatilis): role of beta-adrenergic responses
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