A unique mode of tissue oxygenation and the adaptive radiation of teleost fishes
A unique mode of tissue oxygenation and the adaptive radiation of teleost fishes
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硬骨鱼独特的组织氧合模式和适应性辐射
DOI：
10.1242/jeb.093526
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发表时间：
2014
影响因子：
2.8
通讯作者：
Colin J. Brauner
中科院分区：
文献类型：
--
作者：
David J. Randall;J. Rummer;Jonathan M. Wilson;S. Wang;Colin J. Brauner
硬骨鱼占现存水生脊椎动物的95%，我们认为这部分与它们独特的组织氧合模式有关。我们提出了它们供氧系统进化过程中的一系列事件。首先，鳃和静脉循环中血浆可及的碳酸酐酶（CA）的缺失减慢了雅各布斯-斯图尔特循环和血浆与红细胞（红细胞）之间酸的转移。这改善了全身性酸中毒（与突发游泳能力增加有关）对血红蛋白(Hb) -O2结合的影响。由于红细胞pH值与血浆pH值不耦合，Hb作为缓冲剂的重要性降低。缓冲的减少是由Hb分子上组氨酸残基数量的减少介导的，并导致通过红细胞的O2和CO2转移的增强偶联。在没有血浆CA的情况下，几乎所有的血浆碳酸氢盐最终都通过红细胞脱水成二氧化碳，氯化物/碳酸氢盐交换是二氧化碳排泄的限速步骤。这种通过鳃的二氧化碳排泄模式导致二氧化碳水合/脱水反应的不平衡状态，从而提高了动脉和静脉血浆碳酸氢盐水平。保留了嵌入动脉内皮的血浆可达CA，这消除了局部碳酸氢盐不平衡，形成二氧化碳，然后进入红细胞。因此，红细胞pH值降低，与pH敏感的玻尔/根Hbs一起，动脉氧张力升高，从而增强组织氧合。眼睛和后来的鱼鳔的毛细血管（视网膜）的逆流排列随着鱼鳔的气腺一起进化。这两种安排都增强和放大了二氧化碳和酸的产生，因此，向这些特殊组织分泌氧气。β-肾上腺素能刺激红细胞Na+/H+交换的进化保护应激时鳃对O2的摄取，并进一步增强了血浆对CO2水合/脱水的不平衡状态。最后，红细胞有机磷酸盐（如NTP）可以在缺氧时减少，进一步增加Hb-O2亲和力，而不影响组织O2输送，因为高亲和力的Hbs仍然可以通过玻尔/根位移将O2充分输送到组织。我们认为，这种独特的组织氧转移模式是在三叠纪/侏罗纪时期进化而来的，当时氧气水平很低，最终产生了现存脊椎动物中最广泛的适应性辐射，即硬骨鱼。
Teleost fishes constitute 95% of extant aquatic vertebrates, and we suggest that this is related in part to their unique mode of tissue oxygenation. We propose the following sequence of events in the evolution of their oxygen delivery system. First, loss of plasma-accessible carbonic anhydrase (CA) in the gill and venous circulations slowed the Jacobs–Stewart cycle and the transfer of acid between the plasma and the red blood cells (RBCs). This ameliorated the effects of a generalised acidosis (associated with an increased capacity for burst swimming) on haemoglobin (Hb)–O2 binding. Because RBC pH was uncoupled from plasma pH, the importance of Hb as a buffer was reduced. The decrease in buffering was mediated by a reduction in the number of histidine residues on the Hb molecule and resulted in enhanced coupling of O2 and CO2 transfer through the RBCs. In the absence of plasma CA, nearly all plasma bicarbonate ultimately dehydrated to CO2 occurred via the RBCs, and chloride/bicarbonate exchange was the rate-limiting step in CO2 excretion. This pattern of CO2 excretion across the gills resulted in disequilibrium states for CO2 hydration/dehydration reactions and thus elevated arterial and venous plasma bicarbonate levels. Plasma-accessible CA embedded in arterial endothelia was retained, which eliminated the localized bicarbonate disequilibrium forming CO2 that then moved into the RBCs. Consequently, RBC pH decreased which, in conjunction with pH-sensitive Bohr/Root Hbs, elevated arterial oxygen tensions and thus enhanced tissue oxygenation. Counter-current arrangement of capillaries (retia) at the eye and later the swim bladder evolved along with the gas gland at the swim bladder. Both arrangements enhanced and magnified CO2 and acid production and, therefore, oxygen secretion to those specialised tissues. The evolution of β-adrenergically stimulated RBC Na+/H+ exchange protected gill O2 uptake during stress and further augmented plasma disequilibrium states for CO2 hydration/dehydration. Finally, RBC organophosphates (e.g. NTP) could be reduced during hypoxia to further increase Hb–O2 affinity without compromising tissue O2 delivery because high-affinity Hbs could still adequately deliver O2 to the tissues via Bohr/Root shifts. We suggest that the evolution of 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.
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影响因子：
2.1
作者：
Boron, WF
通讯作者：
Boron, WF
DOI：
--
发表时间：
1999-02
期刊：
The Journal of experimental biology
影响因子：
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作者：
J. B. Claiborne;C. Blackston;Keith P. Choe;D. C. Dawson;S. Harris;L. Mackenzie;A. Morrison-Shetlar
通讯作者：
J. B. Claiborne;C. Blackston;Keith P. Choe;D. C. Dawson;S. Harris;L. Mackenzie;A. Morrison-Shetlar
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DOI：
10.1016/0034-5687(83)90054-3
发表时间：
1983
期刊：
Respiration physiology
影响因子：
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作者：
Lapennas,GN
通讯作者：
Lapennas,GN
大鼠和人骨骼肌毛细血管中碳酸酐酶 IV 的免疫组织化学定位。
DOI：
10.1177/42.9.8064130
发表时间：
1994
期刊：
The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society
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作者：
Sender,S;Gros,G;Waheed,A;Hageman,GS;Sly,WS
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Sly,WS
斑点绿河豚（Tetraodon nigrovirids）鳃中碳酸酐酶 II 和阴离子交换剂 1 的新相关性。
DOI：
10.1002/jez.391
发表时间：
2007
期刊：
Journal of experimental zoology. Part A, Ecological genetics and physiology
影响因子：
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Tang,CH;Lee,TH
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