PUBLICATION
Regulation of erythrocyte function: multiple evolutionary solutions for respiratory gas transport and its regulation in fish
- Authors
- Nikinmaa, M., Berenbrink, M., Brauner, C.J.
- ID
- ZDB-PUB-190519-4
- Date
- 2019
- Source
- Acta physiologica (Oxford, England) 227(2): e13299 (Review)
- Registered Authors
- Nikinmaa, Mikko
- Keywords
- Bohr effect, Oxygen equilibrium curve (OEC), Root effect, adrenergically stimulated Na+/H+ exchange, anion exchange, carbonic anhydrase, erythrocyte
- MeSH Terms
-
- Animals
- Biological Evolution*
- Biological Transport
- Carbon Dioxide/metabolism*
- Erythrocytes/physiology*
- Fishes/physiology*
- Oxygen/metabolism*
- PubMed
- 31102432 Full text @ Acta Physiol. (Oxf).
Citation
Nikinmaa, M., Berenbrink, M., Brauner, C.J. (2019) Regulation of erythrocyte function: multiple evolutionary solutions for respiratory gas transport and its regulation in fish. Acta physiologica (Oxford, England). 227(2):e13299.
Abstract
Gas transport concepts in vertebrates have naturally been formulated based on human blood. However, the first vertebrates were aquatic, and fish and tetrapods diverged hundreds of millions years ago. Water-breathing vertebrates live in an environment with low and variable O2 levels, making environmental O2 an important evolutionary selection pressure in fishes, and various features of their gas transport differ from humans. Erythrocyte function in fish is of current interest, because current environmental changes affect gas transport, and because especially zebrafish is used as a model in biomedical studies, making it important to understand the differences in gas transport between fish and mammals to be able to carry out meaningful studies. Of the close to thirty thousand fish species, teleosts are the most species-numerous group. However, two additional radiations are discussed: agnathans and elasmobranchs. The gas transport by elasmobranchs may be closest to the ancestors of tetrapods. The major difference in their haemoglobin (Hb) function to humans is their high urea tolerance. Agnathans differ from other vertebrates by having Hbs, where cooperativity is achieved by monomer-oligomer equilibria. Their erythrocytes also lack the anion exchange pathway with profound effects on CO2 transport. Teleosts are characterized by highly pH sensitive Hbs, which can fail to become fully O2 -saturated at low pH. An adrenergically stimulated Na+ /H+ exchanger has evolved in their erythrocyte membrane, and plasma-accessible carbonic anhydrase can be differentially distributed among their tissues. Together, and differing from other vertebrates, these features can maximize O2 unloading in muscle while ensuring O2 loading in gills. This article is protected by copyright. All rights reserved.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping