The Generation of Hyperbaric Oxygen Tensions in Fish

Physiology ◽  
2001 ◽  
Vol 16 (6) ◽  
pp. 287-291 ◽  
Author(s):  
Bernd Pelster
Keyword(s):  
Hyperbaric Oxygen ◽  
Carrying Capacity ◽  
Oxygen Supply ◽  
Low Ph ◽  
Swim Bladder ◽  
Root Effect ◽  
Metabolic Adaptations ◽  
Oxygen Tensions ◽  
Gas Gland ◽  
Oxygen Carrying Capacity

Surprising inventiveness in the molecular interactions in fish hemoglobins that express the Root effect (decreased oxygen-carrying capacity at low pH) and in metabolic adaptations in swim bladder gas gland cells and retinal tissues causes local acidification of blood and generates hyperbaric oxygen tensions that drive oxygen into the swim bladder (regulating buoyancy) and ensures the oxygen supply to the avascularized retinae.

scholarly journals Simultaneous exposure to nitrate and low pH reduces the blood oxygen-carrying capacity and functional performance of a freshwater fish

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Daniel F Gomez Isaza ◽  
Rebecca L Cramp ◽  
Craig E Franklin
Keyword(s):  
Carrying Capacity ◽  
Functional Performance ◽  
Swimming Performance ◽  
Low Ph ◽  
Blood Oxygen ◽  
Aerobic Scope ◽  
Simultaneous Exposure ◽  
Post Exercise ◽  
Oxygen Carrying Capacity ◽  
Post Exercise Recovery

Abstract Human activities present aquatic species with numerous of environmental challenges, including excessive nutrient pollution (nitrate) and altered pH regimes (freshwater acidification). In isolation, elevated nitrate and acidic pH can lower the blood oxygen-carrying capacity of aquatic species and cause corresponding declines in key functional performance traits such as growth and locomotor capacity. These factors may pose considerable physiological challenges to organisms but little is known about their combined effects. To characterise the energetic and physiological consequences of simultaneous exposure to nitrate and low pH, we exposed spangled perch (Leiopotherapon unicolor) to a combination of nitrate (0, 50 or 100 mg L−1) and pH (pH 7.0 or 4.0) treatments in a factorial experimental design. Blood oxygen-carrying capacity (haemoglobin concentration, methaemoglobin concentrations and oxygen equilibrium curves), aerobic scope and functional performance traits (growth, swimming performance and post-exercise recovery) were assessed after 28 days of exposure. The oxygen-carrying capacity of fish exposed to elevated nitrate (50 and 100 mg L−1) was compromised due to reductions in haematocrit, functional haemoglobin levels and a 3-fold increase in methaemoglobin concentrations. Oxygen uptake was also impeded due to a right shift in oxygen–haemoglobin binding curves of fish exposed to nitrate and pH 4.0 simultaneously. A reduced blood oxygen-carrying capacity translated to a lowered aerobic scope, and the functional performance of fish (growth and swimming performance and increased post-exercise recovery times) was compromised by the combined effects of nitrate and low pH. These results highlight the impacts on aquatic organisms living in environments threatened by excessive nitrate and acidic pH conditions.

Effects of acute prolonged hypoxia on cardiovascular dynamics in dogs

1977 ◽  
Vol 43 (5) ◽  
pp. 784-789 ◽  
Author(s):  
J. F. Borgia ◽  
S. M. Horvath
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Cardiac Index ◽  
Carrying Capacity ◽  
Hemoglobin Concentration ◽  
Severe Hypoxia ◽  
Systemic Hypertension ◽  
Anesthetized Dogs ◽  
Oxygen Tensions ◽  
Oxygen Carrying Capacity

Intact anesthetized dogs were exposed for 75 min to either 5.75, 9.0, or 12.0% oxygen in nitrogen. Although pulmonary artery pressures were significantly elevated in all hypoxic exposures, systemic hypertension occurred only at the onset of severe hypoxia(5.75% O2). Coronary blood flow increased from an average of 130 during normoxia to a peak of 400 ml/100 g per min during inhalation of 5.75% O2, and coronary sinus oxygen tensions of 8 Torr and oxygen contents of 1.1 ml/100 ml were sustained for 75 min without biochemical, functional, or electrophysiological evidence of myocardial ischemia. Cardiac index (CI) increased significantly only during severe hypoxia (5.75% O2) with the greatest elevation after 30 min. Subsequently, CI decreased concomitantly with a 27% elevation in arterial hemoglobin concentration and oxygen-carrying capacity. It is concluded that the hypoxic threshold for significant elevations of cardiac output is between 6.0 and 9.0% O2.

pH-dependent proton secretion in cultured swim bladder gas gland cells

1997 ◽  
Vol 273 (5) ◽  
pp. R1719-R1725 ◽  
Author(s):  
B. Pelster ◽  
H. Niederstätter
Keyword(s):  
Acid Production ◽  
Ph Dependence ◽  
Low Ph ◽  
Swim Bladder ◽  
Proton Secretion ◽  
Gland Cells ◽  
Sodium Dependent ◽  
Acid Release ◽  
Decreasing Ph ◽  
Gas Gland

The pH dependence of acid production and of acid release has been analyzed in cultured gas gland cells of the European eel using a cytosensor microphysiometer. Total acid release of gas gland cells showed an optimum at pH 7.4–7.6, with only a minor reduction at acidic (pH 7.0) as well as at alkaline pH (pH 8.0). The acid production was largely dependent on the availability of extracellular glucose and was almost completely abolished if glucose was replaced by succinate, alanine, or even pyruvate. Phloretin, an inhibitor of glucose uptake, significantly reduced acid release of gas gland cells with a K i of ∼1 × 10−5 M, irrespective of pH. Although the glucose dependence of acid production was not modified by pH, acid release became increasingly sodium dependent with decreasing pH, but at low pH significantly higher sodium concentrations were necessary to achieve maximal rate of proton secretion. This sodium-dependent proton secretion could only in part be inhibited by application of 5-( N-methyl- N-isobutyl)-amiloride. Removal of extracellular potassium caused a slow reduction in the rate of acid secretion. A similar reduction was observed in the presence of ouabain, a specific inhibitor of Na+-K+-adenosinetriphosphatase, and both effects significantly increased with decreasing pH. The results demonstrate a significant pH dependence of the mechanisms of acid release in swim bladder gas gland cells and indicate that sodium-dependent pathways become especially important at low pH.

Oxygen Carrying Capacity and Oxygen Supply Rate of Artificial Oxygen Carrier, Neo Red Cell (NRC)

1998 ◽  
Vol 26 (5-6) ◽  
pp. 455-464 ◽  
Author(s):  
Tetsuhiro Kimura ◽  
Hiroshi Kurosawa ◽  
Hiroshi Goto ◽  
Shinichi Kora ◽  
Yoshitaka Ogata ◽  
...  
Keyword(s):  
Carrying Capacity ◽  
Oxygen Supply ◽  
Oxygen Carrier ◽  
Red Cell ◽  
Supply Rate ◽  
Artificial Oxygen Carrier ◽  
Oxygen Carrying Capacity ◽  
Oxygen Supply Rate

The functional significance of adrenergic pH regulation in fish erythrocytes

1989 ◽  
Vol 67 (1) ◽  
pp. 235-238 ◽  
Author(s):  
Bruce L. Tufts ◽  
D. J. Randall
Keyword(s):  
Carrying Capacity ◽  
Functional Significance ◽  
Oncorhynchus Tshawytscha ◽  
Ph Regulation ◽  
Ph Effect ◽  
Blood Oxygen ◽  
Adrenergic Stimulation ◽  
Root Effect ◽  
Oxygen Carrying Capacity

Experiments were conducted in vitro to determine the presence or absence of an adrenergic pH effect in the erythrocytes of Squalus suckleyi, Raja binoculata, and Oncorhynchus tshawytscha. Adrenergic stimulation significantly increased the erythrocyte pH of Oncorhynchus tshawytscha, but did not significantly affect the erythrocyte pH of Squalus suckleyi or Raja binoculata. The results support the view that the functional significance of adrenergic pH regulation in fish erythrocytes is to offset the reduction in blood oxygen carrying capacity caused by the Root effect.

scholarly journals Adrenalin-Induced Na+/H+ Exchange in' Trout Erythrocytes and its Effects Upon Oxygen-Carrying Capacity

1985 ◽  
Vol 118 (1) ◽  
pp. 229-246 ◽  
Author(s):  
A. R. COSSINS ◽  
P. A. RICHARDSON
Keyword(s):  
Steady State ◽  
Intracellular Ph ◽  
Carrying Capacity ◽  
Extracellular Ph ◽  
Extracellular Medium ◽  
Root Effect ◽  
Fish Blood ◽  
Wide Range ◽  
Oxygen Carrying Capacity ◽  
Normal Relationship

Addition of adrenalin (10−4moll−1) to trout erythrocytes in an unbuffered saline resulted in a rapid acidification of the extracellular medium. This process was inhibited by amiloride (K½10−4moll−1) and by the removal of extracellular Na+. The rate of acidification was a saturable function of extracellular Na+ concentration. When extracellular pH was maintained constant by continual titration with KOH, adrenalin induced a transient burst of H+ efflux. During this period the loss of cellular H+ equivalents was approximately equal to the net gain of Na+, providing evidence for a Na+/H+ exchange with a stoichiometry of 1. The steady state following stimulation with adrenalin could be disturbed by changes in extracellular pH. After the addition of adrenalin, intracellular pH (pHi) was increased by 0.2-0.3 units but did not exceed extracellular pH, as required if the Na+ and H+ concentration ratios came into equilibrium. The increase in pHi in stimulated compared with control cells was maintained approximately constant over a wide range of pHo, suggesting that pH equilibration by the Jacob-Stewart cycle was operating normally and that the activation of Na+/H+ exchange provides an offset to the normal relationship between pHi and pHo. The steady state results from a balance of an increase Na+/H+ and CI−/HCO3− exchange with an increased rate of Na+ pumping and next KCl efflux. In a buffered saline, adrenalin caused a 22–46% increase in the oxygen-carrying capacity of trout erythrocytes. It is suggested that this was due to a Root effect of trout haemoglobin caused by cellular alkalinization when the Na+/H+ exchange mechanism was activiated. This observation suggests that many published values for oxygencarrying capacity of fish blood require re-evaluation.

Layer-by-layer assembly of hemoglobin-coated microspheres for enhancing the oxygen carrying capacity

RSC Advances ◽  
2016 ◽  
Vol 6 (65) ◽  
pp. 59984-59987 ◽  
Author(s):  
Lijun Sun ◽  
Yannan Lu ◽  
Zhongqin Pan ◽  
Tingting Wu ◽  
Xiaojun Liu ◽  
...  
Keyword(s):  
Carrying Capacity ◽  
Layer By Layer ◽  
Layer By Layer Assembly ◽  
Oxygen Carrying Capacity ◽  
Layer Assembly

Hemoglobin-coated microspheres with one layer and five layers were fabricated by layer-by-layer assembly.

scholarly journals EVALUATION OF A STROMA-FREE HEMOGLOBIN SOLUTION FOR USE AS A PLASMA EXPANDER

1967 ◽  
Vol 126 (6) ◽  
pp. 1127-1142 ◽  
Author(s):  
S. Frederick Rabiner ◽  
J. Raymond Helbert ◽  
Harry Lopas ◽  
Lila H. Friedman
Keyword(s):  
Carrying Capacity ◽  
Vital Signs ◽  
Free Hemoglobin ◽  
Hemoglobin Solution ◽  
Plasma Expander ◽  
Chronic Effects ◽  
Coagulant Activity ◽  
Methemoglobin Formation ◽  
Oxygen Carrying Capacity ◽  
Acute And Chronic Effects

The preparation of large quantities of a stable, stroma-free hemoglobin solution without coagulant activity is described. Following infusion of this solution into phlebotomized dogs, there is no methemoglobin formation, no adverse effects on vital signs, and no demonstrable activation of blood coagulation. The hemoglobin maintains its oxygen-carrying capacity and liberates oxygen into tissues. Acute and chronic effects on renal function following infusion of this preparation were also studied and no effect on clearance of urea, creatinine, or P.A.H. could be demonstrated. There was no change in urinary output and histological sections revealed no lesions attributable to hemoglobin toxicity. It is concluded that a stroma-free hemoglobin solution may have use as a plasma expander.

scholarly journals Oxygen carrying capacity of completely artificial red blood cell substitute : Liposome-embedded-heme

1990 ◽  
Vol 4 (6) ◽  
pp. 676-680
Author(s):  
Koichi Kobayashi ◽  
Masazumi Watanabe ◽  
Toshinori Hashizume ◽  
Masabumi Kawamura ◽  
Ryoichi Kato ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Carrying Capacity ◽  
Oxygen Carrying Capacity
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