The Physiology of Carbon Dioxide Transport in Insect Blood

1950 ◽  
Vol 27 (2) ◽  
pp. 158-174 ◽  
Author(s):  
L. LEVENBOOK
Keyword(s):  
Carbon Dioxide ◽  
Dissociation Constant ◽  
Temperature Coefficient ◽  
Carbonic Acid ◽  
Apparent Dissociation Constant ◽  
Carbon Dioxide Transport ◽  
High Co2 ◽  
The Third ◽  
A Value ◽  
Dissociation Curves

1. The pH of the blood of the third instar Gastrophilus larva is 6.64 at 38° C. with a pH-temperature coefficient of -0.007 Per 1° C. rise in temperature. 2. The total CO2 content of the blood varies from 40.6 to 131.4 vol. % with an average of 72.4 vol. %. The CO2 content of the tissues minus the cuticle is very close to, and follows the variations in, the CO2 content of the blood. 3. The CO2 tension in the blood is from 300 to 500 mm. Hg. From 30 to 50% of the CO2 is in solution, the rest in the form of bicarbonate. Carbamate formation does not occur in the blood. 4. The ‘apparent’ dissociation constant for carbonic acid, (pK'1), has a value of 6.08 (S.D. ±0.06) at 38° C. and 6.19 (s.d. ±0.13) at 16° C. 5. CO2 dissociation curves have been drawn for 38 and 16° C. The slope of the curves indicates that the whole of the CO2 is given off at zero CO2 tension, and that the blood is adapted for functioning at high CO2 tensions.

scholarly journals Oxygen and Carbon Dioxide Transport Characteristics of the Blood of the Nile Monitor Lizard (Varanus Niloticus)

1987 ◽  
Vol 130 (1) ◽  
pp. 27-38
Author(s):  
JAMES W. HICKS ◽  
ATSUSHI ISHIMATSU ◽  
NORBERT HEISLER
Keyword(s):  
Carbon Dioxide ◽  
Haemoglobin Concentration ◽  
Oxygen Affinity ◽  
Total Blood ◽  
Carbon Dioxide Transport ◽  
Monitor Lizard ◽  
The Right ◽  
Dissociation Curves

Oxygen and carbon dioxide dissociation curves were constructed for the blood of the Nile monitor lizard, Varanus niloticus, acclimated for 12h at 25 and 35°C. The oxygen affinity of Varanus blood was low when Pco2 w a s in the range of in vivo values (25°C: P50 = 34.3 at PCOCO2 = 21 mmHg; 35°C: P50 = 46.2 mmHg at PCOCO2 = 35 mmHg; 1 mmHg = 133.3 Pa), and the oxygen dissociation curves were highly sigmoidal (Hill's n = 2.97 at 25°C and 3.40 at 35°C). The position of the O2 curves was relatively insensitive to temperature change with an apparent enthalpy of oxygenation (ΔH) of −9.2kJ mol−1. The carbon dioxide dissociation curves were shifted to the right with increasing temperature by decreasing total CCOCO2 at fixed PCOCO2, whereas the state of oxygenation had little effect on total blood CO2 content. The in vitro buffer value of true plasma (Δ[HCO3−]pl/-ΔpHpl) rose from 12.0 mequiv pH−1−1 at 25°C to 17.5 mequiv pH−11−1 at 35°C, reflecting a reversible increase of about 30% in haemoglobin concentration and haematocrit levels during resting conditions in vivo.

Which value for the first dissociation constant of carbonic acid should be used in biological work?

1991 ◽  
Vol 260 (5) ◽  
pp. C1113-C1116 ◽  
Author(s):  
R. W. Putnam ◽  
A. Roos
Keyword(s):  
Ionic Strength ◽  
Activity Coefficient ◽  
Dissociation Constant ◽  
Carbonic Acid ◽  
Mass Action ◽  
Bicarbonate Concentration ◽  
Apparent Dissociation Constant ◽  
Logarithmic Form ◽  
Ion Activity ◽  
Hasselbalch Equation

The apparent first dissociation constant of carbonic acid has been defined in different ways in the literature. Harned and co-workers (8-10) have defined it in terms of molalities of the participating species, including H ions: Ks = mHmHCO3/mCO2. In contrast, Hastings and Sendroy have defined an apparent constant in which acidity is expressed as H ion activity: K'1 = aHmHCO3/mCO2. These constants differ by a factor gamma H, the activity coefficient of H ions at the prevailing ionic strength. Therefore, pK'1 is greater than pKs by an amount equal to -log gamma H, which, at mu = 0.16 M, is approximately 0.1. It is important that the correct value for the apparent dissociation constant or its logarithmic form be entered in the mass action expression or in the Henderson-Hasselbalch equation in order to prevent significant errors in the computation by means of these equations of quantities that cannot be directly measured. Specifically, for the derivation of bicarbonate concentration from PCO2 and pH (-log aH), pK'1 is to be used and not an uncorrected pKs.

scholarly journals IN VITRO INTERACTIONS BETWEEN OXYGEN AND CARBON DIOXIDE TRANSPORT IN THE BLOOD OF THE SEA LAMPREY (PETROMYZON MARINUS)

1992 ◽  
Vol 173 (1) ◽  
pp. 25-41 ◽  
Author(s):  
R. A. Ferguson ◽  
N. Sehdev ◽  
B. Bagatto ◽  
B. L. Tufts
Keyword(s):  
Carbon Dioxide ◽  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Whole Blood ◽  
Blood Cells ◽  
Sea Lamprey ◽  
Carbon Dioxide Transport ◽  
Dissociation Curves

In vitro experiments were carried out to examine the interactions between oxygen and carbon dioxide transport in the blood of the sea lamprey. Oxygen dissociation curves for whole blood obtained from quiescent lampreys had Hill numbers (nH) ranging from 1.52 to 1.89. The Bohr coefficient for whole blood was -0.17 when extracellular pH (pHe) was considered, but was much greater (-0.63) when red blood cell pH (pHi) was considered. The pHi was largely dependent on haemoglobin oxygen- saturation (SO2) and the pH gradient across the red blood cell membrane was often reversed when PCO2 was increased and/or SO2 was lowered. The magnitude of the increase in pHi associated with the Haldane effect ranged from 0.169 pH units at 2.9 kPa PCO2 to 0.453 pH units at a PCO2 of 0.2 kPa. Deoxygenated red blood cells had a much greater total CO2 concentration (CCO2) than oxygenated red blood cells, but the nonbicarbonate buffer value for the red blood cells was unaffected by oxygenation. Plasma CCO2 was not significantly different under oxygenated or deoxygenated conditions. Partitioning of CO2 carriage in oxygenated and deoxygenated blood supports recent in vivo observations that red blood cell CO2 carriage can account for much of the CCO2 difference between arterial and venous blood. Together, the results also suggest that oxygen and carbon dioxide transport may not be tightly coupled in the blood of these primitive vertebrates. Finally, red cell sodium concentrations were dependent on oxygen and carbon dioxide tensions in the blood, suggesting that sodium-dependent ion transport processes may contribute to the unique strategy for gas transport in sea lamprey blood.

A Passive Model of the Heat, Oxygen and Carbon Dioxide Transport in the Human Body

2009 ◽  
Author(s):  
Cyro Albuquerque-Neto ◽  
Jurandir Itizo Yanagihara
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Human Body ◽  
Circular Cross Section ◽  
The Body ◽  
Heat Equations ◽  
Carbon Dioxide Transport ◽  
Small Vessels ◽  
Hands And Feet ◽  
Dissociation Curves

The aim of this work is the development of a mathematical model which integrates a model of the human respiratory system and a model of the human thermal system. Both models were previously developed at the same laboratory, based on classical works. The human body was divided in 15 segments: head, neck, trunk, arms, forearms, hands, thighs, legs and feet. Those segments have the form of a cylinder (circular cross-section) or a parallelogram (hands and feet) with the following tissue layers: muscle, fat, skin, bone, brain, lung, heart and viscera. Two different geometries are used to model the transport of mass and heat in the tissues. For the mass transfer, those layers are considered as tissue compartments. For the heat transfer, the body geometry is taken into account. Each segment contains an arterial and a venous compartment, representing the large vessels. The blood in the small vessels are considered together with the tissues. The gases are transported by the blood dissolved and chemically reacted. Metabolism takes place in the tissues, where oxygen is consumed generating carbon dioxide and heat. In the lungs, mass transfer happens by diffusion between an alveolar compartment and several pulmonary capillaries compartments. The skin exchanges heat with the environment by convection, radiation and evaporation. The differential transport equations were obtained by heat and mass balances. The discretization heat equations were obtained applying the finite volume method. The regulation mechanisms were considered as model inputs. The results show three different environment situations. It was concluded that the gas transport is most influenced by the temperature effects on the blood dissociation curves and the metabolism rise in a cold environment by shivering.

Antistaphylococcal activity of carbonic acid extract of hops

2018 ◽  
Vol 22 (2) ◽  
pp. 297-300
Author(s):  
V.V. Nevmerzhitsky ◽  
V.Yu. Ivannik ◽  
V.V. Kazmirchuk ◽  
T.N. Moiseenko ◽  
T.A. Volkov ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Antimicrobial Agents ◽  
Carbonic Acid ◽  
Inflammatory Diseases ◽  
Acquired Resistance ◽  
Biologically Active ◽  
Antibacterial Drugs ◽  
Antistaphylococcal Activity ◽  
Prevention And Treatment ◽  
Main Disadvantage

The fight against staphylococcal infection, increasing the effectiveness of methods of prevention and treatment of diseases of staphylococcal etiology is of interest to scientists and practitioners, both in Ukraine and around the world. The urgency of this problem is growing rapidly, as there is a tendency to increase the resistance of not only staphylococci, but also other gram-positive bacteria. The spread of methicillin-resistant staphylococci restricts the choice of antibiotics for the treatment of diseases of staphylococcal etiology. Staphylococcus aureus is the most common and dangerous type, which is one of the main factors of purulent-inflammatory lesions of the skin and mucous membranes. As a result of mutations, pathogenic staphylococci acquired resistance to antibacterial drugs. The main disadvantage of modern antibiotics is their non-selectivity. As a result of mutations, pathogenic staphylococci acquired resistance to antibacterial drugs. The main disadvantage of modern antibiotics is their non-selectivity. One of the unique and promising medicinal plants, which contains a rich complex of biologically active substances (BAS), is common hops (Humulus lupulus L.). The complex of BAS (flavonoids, hormones, vitamins, bitter, phenolic compounds, essential oils) causes anti-inflammatory, bactericidal, hyposensitizing and analgesic action of hops. The purpose of this work is to determine the antistaphylococcal activity of the carbon dioxide extract of hops and to justify the development on its basis of new antimicrobial agents for the prevention and treatment of infectious and purulent-inflammatory diseases. The following methods were used: microbiological (method of diffusion into agar (well method)) and mathematical and statistical. The high antimicrobial activity of the carbon dioxide extract of hops has been established for museum test strains of the genus Staphylococcus. The results of the studies testify to the prospects of further study of the bactericidal properties of the extract of hops carbon dioxide with the aim of creating effective antimicrobial agents on its basis for the prevention and treatment of infectious and purulent-inflammatory diseases of staphylococcal etiology.

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