THE INFLUENCE OF SALINITY ACCLIMATION ON THE TEMPERATURE SENSITIVITY OF OXYGEN BINDING TO THE HAEMOCYANIN OF THE PROSOBRANCH NEPTUNEA ANTIQUA

1990 ◽  
Vol 149 (1) ◽  
pp. 417-424 ◽  
Author(s):  
O. L. E. BRIX ◽  
SAVERIO G. CONDO ◽  
ALFREDO COLOSIMO ◽  
BRUNO GIARDINA
Keyword(s):  
Temperature Sensitivity ◽  
Whole Blood ◽  
Thermal Sensitivity ◽  
Ionic Concentration ◽  
Oxygen Binding ◽  
Salinity Acclimation ◽  
Ph Dependent

The thermal sensitivity of oxygen binding has been studied at 10, 15, 20 and 25 °C in whole blood from specimens of Neptunea antiqua acclimated to ambient salinities of 24 and 35‰. The O2 affinity is strongly pH-dependent, demonstrating a large reversed Bohr shift below pH8.0. The magnitude of the Bohr shift is not significantly influenced by temperature or ionic concentration. At 35‰, the blood O2-affinity is strongly influenced by temperature (δHapp-≈58.6kJmol−1), while at 24‰ there is almost no temperature sensitivity (δHapp<-18.8kJmol−1)

The in vitro respiratory and acid–base properties of blood and tissue from the Kemp's ridley sea turtle, Lepidochelys kempi

1994 ◽  
Vol 72 (8) ◽  
pp. 1403-1408 ◽  
Author(s):  
Erich K. Stabenau ◽  
Thomas A. Heming
Keyword(s):  
Temperature Sensitivity ◽  
Whole Blood ◽  
Sea Turtles ◽  
Hill Coefficient ◽  
Acid Base ◽  
Kemp's Ridley Sea Turtles ◽  
Dissociation Curves ◽  
Kemp's Ridley ◽  
Base Properties

We determined the in vitro respiratory and acid–base properties of blood and tissue from Kemp's ridley sea turtles (Lepidochelys kempi). Blood O2 dissociation curves of ridley turtles were sigmoid, with a P50 of 31.2 ± 0.3 (mean ± SD) torr at 25 °C and pH 7.51. Increments in temperature or [Formula: see text] were associated with a shift of the O2 dissociation curves to the right and, hence, a reduction in haemoglobin–O2 binding affinity. The apparent heat of oxygenation, which is a measure of the temperature sensitivity of haemoglobin–O2 affinity, was −10.5 kcal/mol O2. The degree of cooperativity of O2 for hemoglobin binding sites, as measured by the Hill coefficient, increased at higher temperatures (20–30 °C at a [Formula: see text] of 37 torr), but was unaffected by changes in [Formula: see text] (37–52 torr at 25 °C). The CO2-Bohr effect was −0.34 torr/pH unit. The CO2 capacitance coefficient of whole blood and plasma declined as a function of increased [Formula: see text] (22 °C). Non-bicarbonate buffer capacities (22 °C) were 19.7, 18.5, and 6.4 slykes for whole blood, true plasma, and separated plasma, respectively. The skeletal muscle myoglobin content was 3.1 ± 0.84 mg∙g−1 of tissue. The respiratory and acid–base properties of blood and tissue from Kemp's ridley sea turtles are consistent with those of species that utilize lung O2 stores during long-term aerobic dives. The enhanced haemoglobin–O2 temperature sensitivity exhibited by the ridley turtle could be a physiological adaptation for life in coastal environments that typically undergo substantial fluctuations in temperature.

scholarly journals ALLOSTERIC CONTROL OF OXYGEN BINDING BY HAEMOGLOBIN DURING EMBRYONIC DEVELOPMENT IN THE CROCODILE CROCODYLUS POROSUS: THE ROLE OF RED CELL ORGANIC PHOSPHATES AND CARBON DIOXIDE

1993 ◽  
Vol 175 (1) ◽  
pp. 15-32 ◽  
Author(s):  
G. C. Grigg ◽  
R. M. G. Wells ◽  
L. A. Beard
Keyword(s):  
Embryonic Development ◽  
Whole Blood ◽  
Marked Effect ◽  
Oxygen Affinity ◽  
Oxygen Binding ◽  
Blood Oxygen ◽  
Embryonic Life ◽  
Crocodylus Porosus ◽  
Blood Oxygen Affinity ◽  
2,3 Dpg

The P50 of whole blood [30°C, PCO2=2.08 kPa (15.6 mmHg)] decreases during embryonic development from approximately 6.7 kPa (50 mmHg) at 15 days to about half this value at hatching (86 days), paralleling a decrease in ATP from 100 to 5–10 micromole g-1 Hb. There is also a progressive changeover from embryonic to adult haemoglobin (HbA). A pulse of 2,3- diphosphoglycerate (2,3-DPG) (18 micromole g-1 Hb) occurs late in embryonic life. It has no effect on whole-blood oxygen-affinity and falls rapidly at hatching to values typical of post-hatchling crocodilians in general (<1.0 micromole g-1 Hb). ATP has a marked effect on the oxygen affinity of embryonic haemoglobin (HbE) but not on HbA. 2,3-DPG has only very small effects on the oxygen affinities of HbE and HbA. CO2 has a small effect on the oxygen affinity of HbE but a marked effect on that of HbA. Values of PO2 measured in the chorio-allantoic artery [2.9 kPa (22 mmHg)] and vein [5.9 kPa (52 mmHg)] imply an increase in saturation from approximately 30 % to more than 80 %. Neither whole-blood oxygen-affinity nor ATP level was altered in response to an experimental 7-day exposure to low ambient oxygen levels [10.7 kPa (80 mmHg)]. The results do not lend themselves easily to the pan-selectionist paradigm in which all physiological traits are viewed as being adaptive.

Oxygen binding in alligator blood related to temperature, diving, and "alkaline tide"

1986 ◽  
Vol 251 (5) ◽  
pp. R901-R908 ◽  
Author(s):  
R. E. Weber ◽  
F. N. White
Keyword(s):  
Temperature Sensitivity ◽  
Bohr Effect ◽  
Alligator Mississippiensis ◽  
Breath Holding ◽  
Oxygen Binding ◽  
Constant Ph ◽  
The Face ◽  
High O2 ◽  
Alkaline Tide

Blood of Alligator mississippiensis has a relatively high O2 affinity, the half-saturation O2 tension (P50) = 24.5 Torr at pH 7.495, the arterial, normocapnic pH at 25 degrees C. Although the overall temperature sensitivity of P50 at 15, 25, and 35 degrees C and constant pH is low, the effect on P50 almost doubles when measured at the in vivo pH of each temperature (delta Happ = -24 and -47 kJ/mol, respectively). The CO2 Bohr effect (theta CO2 = -0.95) is 5.5 times greater than the fixed acid Bohr effect (theta FA), and the Haldane effect is small (approximately 0.03 pH units). The relatively high O2 affinity may ensure efficient utilization of the lung O2 reserve during breath holding and diving, whereas its pronounced in vivo temperature sensitivity may be adaptive to the high temperature quotients of the organismic O2 requirement. The large difference between theta CO2 and theta FA will favor constancy in blood O2 affinity in the face of large activity-induced increases in blood lactate and pronounced feeding-induced alkaloses. These "alkaline tides," which result from an exchange of plasma Cl- for HCO-3 across the gut wall, appear to be only slightly compensated by increased blood CO2 tensions. The results are additionally discussed in terms of allosteric modulation of hemoglobin-O2 affinity in crocodilians.

Regulation of Blood Oxygen Affinity in the Australian Blackfish Gadopsis Marmoratus: I. Correlations between Oxygen-binding Properties, Habitat and Swimming Behaviour

1982 ◽  
Vol 99 (1) ◽  
pp. 223-243
Author(s):  
G. P. DOBSON ◽  
J. BALDWIN
Keyword(s):  
Whole Blood ◽  
Oxygen Affinity ◽  
Swimming Behaviour ◽  
Oxygen Binding ◽  
Blood Oxygen ◽  
Low Oxygen ◽  
Binding Properties ◽  
Molar Ratios ◽  
Blood Oxygen Affinity ◽  
Low Oxygen Affinity

1. The regulation of whole blood oxygen affinity in the freshwater blackfish Gadopsis marmoratus Richardson has been examined, and correlations made between oxygen-binding properties and the habitat and swimming behaviour of the fish. 2. Blackfish whole blood has a low oxygen affinity relative to other fish bloods reported in the literature. This is not due to a low oxygen affinity of the stripped haemoglobins, but arises from interactions between haemoglobin and intraerythrocytic modulators. 3. The presence of high concentrations of ATP, and to a lesser extent GTP, in the erythrocyte, together with the effect of these nucleoside triphosphates on the oxygen affinity of haemoglobin solutions at physiological NTP: Hb4 molar ratios, demonstrates that this class of compounds is a major regulator of oxygen affinity in blackfish blood. 4. The oxygen affinities of whole blood and haemoglobin solutions are sensitive to pH, with haemoglobin solutions displaying a relatively large alkaline Bohr coefficient of - 1.05 over the physiologically relevant pH range of 6.5–7.0. 5. Although increasing Pco2, lowers the oxygen affinity of whole blood, it does so only through the effect on pH, as pH-buffered haemoglobin solutions show no oxygen-linked CO2 binding. This lack of oxygen-linked CO2 binding has not been reported for any other naturally occurring vertebrate haemoglobins. 6. Muscle morphology and biochemistry, and behavioural observations, indicate that the blackfish uses anaerobic energy metabolism during rapid swimming and in recovery. 7. It is concluded that the oxygen-binding properties of blackfish blood reflect adaptations for maintaining adequate tissue oxygenation for animals at rest and during slow sustained swimming in waters of high oxygen tensions.

scholarly journals High affinity and temperature sensitivity of blood oxygen binding in Pangasianodon hypophthalmus due to lack of chloride-hemoglobin allosteric interaction

2015 ◽  
Vol 308 (11) ◽  
pp. R907-R915 ◽  
Author(s):  
Christian Damsgaard ◽  
Le My Phuong ◽  
Do Thi Thanh Huong ◽  
Frank B. Jensen ◽  
Tobias Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Sensitivity ◽  
Oxygen Binding ◽  
Binding Properties ◽  
Root Effect ◽  
Air Breathing ◽  
Pangasianodon Hypophthalmus ◽  
Effects Of Temperature ◽  
High Temperature Sensitivity ◽  
Binding Curves

Air-breathing fishes represent interesting organisms in terms of understanding the physiological changes associated with the terrestrialization of vertebrates, and, further, are of great socio-economic importance for aquaculture in Southeast Asia. To understand how environmental factors, such as high temperature, affect O2 transport in air-breathing fishes, this study assessed the effects of temperature on O2 binding of blood and Hb in the economically important air-breathing fish Pangasianodon hypophthalmus. To determine blood O2 binding properties, blood was drawn from resting cannulated fishes and O2 binding curves made at 25°C and 35°C. To determine the allosteric regulation and thermodynamics of Hb O2 binding, Hb was purified, and O2 equilibria were recorded at five temperatures in the absence and presence of ATP and Cl−. Whole blood had a high O2 affinity (O2 tension at half saturation P50 = 4.6 mmHg at extracellular pH 7.6 and 25°C), a high temperature sensitivity of O2 binding (apparent heat of oxygenation Δ Happ = −28.3 kcal/mol), and lacked a Root effect. Further, the data on Hb revealed weak ATP binding and a complete lack of Cl− binding to Hb, which, in part, explains the high O2 affinity and high temperature sensitivity of blood O2 binding. This study demonstrates how a potent mechanism for increasing O2 affinity is linked to increased temperature sensitivity of O2 transport and provides a basic framework for a better understanding of how hypoxia-adapted species will react to increasing temperatures.

scholarly journals Stimuli-Responsive Materials: Protein/Polymer-Based Dual-Responsive Gold Nanoparticles with pH-Dependent Thermal Sensitivity (Adv. Funct. Mater. 7/2012)

2012 ◽  
Vol 22 (7) ◽  
pp. 1322-1322 ◽  
Author(s):  
Malte S. Strozyk ◽  
Munish Chanana ◽  
Isabel Pastoriza-Santos ◽  
Jorge Pérez-Juste ◽  
Luis M. Liz-Marzán
Keyword(s):  
Gold Nanoparticles ◽  
Thermal Sensitivity ◽  
Stimuli Responsive ◽  
Responsive Materials ◽  
Protein Polymer ◽  
Dual Responsive ◽  
Ph Dependent

Protein/Polymer-Based Dual-Responsive Gold Nanoparticles with pH-Dependent Thermal Sensitivity

2012 ◽  
Vol 22 (7) ◽  
pp. 1436-1444 ◽  
Author(s):  
Malte S. Strozyk ◽  
Munish Chanana ◽  
Isabel Pastoriza-Santos ◽  
Jorge Pérez-Juste ◽  
Luis M. Liz-Marzán
Keyword(s):  
Gold Nanoparticles ◽  
Thermal Sensitivity ◽  
Protein Polymer ◽  
Dual Responsive ◽  
Ph Dependent
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