Contributions of bicarbonate ion and of dissolved CO2 to expired CO2 in dogs

1960 ◽  
Vol 198 (1) ◽  
pp. 78-88 ◽  
Author(s):  
Francis P. Chinard ◽  
Theodore Enns ◽  
Mary F. Nolan
Keyword(s):  
Blood Stream ◽  
Test Solution ◽  
Dilution Technique ◽  
Dissolved Carbon ◽  
Arterial Blood ◽  
Dissolved Carbon Dioxide ◽  
Anesthetized Dogs ◽  
Peripheral Arterial ◽  
The Right ◽  
Alveolar Capillary

The indicator-dilution technique has been applied to the heart-lung system of anesthetized dogs with injection of test solutions into the right ventricle or pulmonary artery, collection of some thirty anaerobic blood samples over a period of 1 minute from a carotid artery, and collection of expired gases. The test solution contained a reference substance (Na22 or T-1824), labeled water, and C-13- or C-14-labeled HCO3– or dissolved CO2. Under control conditions, losses of the carbon isotopes from the blood stream and recoveries in the expired air indicated equilibration of CO2 amongst its several forms in the time of transit from the site of injection to the alveoli. After administration of acetazoleamide in dosages of 100 down to 20 mg/kg, fractional losses of labeled dissolved carbon dioxide increased by a factor of 4. Confirmatory results were obtained in experiments on the incorporation of O18 from H2O18 into expired CO2. It is concluded that, after inhibition of carbonic anhydrase, peripheral arterial blood differs in composition from end-alveolar capillary blood.

Diffusion and solubility factors in pulmonary inert gas exchanges

1961 ◽  
Vol 16 (5) ◽  
pp. 831-836 ◽  
Author(s):  
Francis P. Chinard ◽  
Theodore Enns ◽  
Mary F. Nolan
Keyword(s):  
Diffusion Coefficients ◽  
Inert Gases ◽  
Limiting Factor ◽  
Gas Exchanges ◽  
Arterial Blood ◽  
Concentration Time ◽  
Anesthetized Dogs ◽  
The Right ◽  
Alveolar Capillary ◽  
Made In

Comparisons have been made in anesthetized dogs of the relative recoveries in arterial blood of pairs of inert gases injected as solutions into the right heart or as gas mixtures into the trachea. The gases differed in their diffusion coefficients or in their solubility. The pairs used were: tritium and Kr85; ethylene-C14 and Xe133. The ratios of the recoveries of the gases approached the ratios of their solubilities and not the ratios of their diffusion coefficients. The site of injection had no significant effect. The concentration-time curves remain proportional during the first passage through the lungs. Diffusion equilibrium is attained within the time of passage of blood through the alveolar capillary. There is no evidence of a diffusion limitation on the exchange of gases with diffusion coefficients as small as that of xenon. Solubility is the limiting factor. Submitted on April 12, 1961

CARDIORENAL EFFECTS OF LARGE INFUSIONS OF DEXTRAN IN DOGS

1954 ◽  
Vol 32 (1) ◽  
pp. 559-566 ◽  
Author(s):  
C. W. Gowdey ◽  
I. E. Young
Keyword(s):  
Cardiac Output ◽  
Peripheral Resistance ◽  
The Body ◽  
Arterial Blood ◽  
High Output Heart Failure ◽  
Mean Pressure ◽  
Anesthetized Dogs ◽  
The Right ◽  
Dextran Solution ◽  
High Output

The production of hypervolemic dilution anemia in intact, anesthetized dogs by the continuous intravenous infusion of 6% dextran solution caused large increases in the cardiac output and urine flow. No consistent changes were observed in pulse rate or arterial blood pressure. The right auricular mean pressure usually increased early in the infusion, but later there was no consistent relation between right auricular pressure and cardiac output. The total peripheral resistance, glomerular filtration rate, and renal blood flow decreased. With infusion volumes exceeding 10% of the body weight, acute high-output heart failure occurred. The observed hemodilution was consistently greater than that expected from the volume of the infusion, because the dextran solution was, presumably, hypertonic.

Renal handling of exogenous and metabolic carbon dioxide

1964 ◽  
Vol 206 (2) ◽  
pp. 362-368 ◽  
Author(s):  
Francis P. Chinard ◽  
Mary F. Nolan ◽  
Theodore Enns
Keyword(s):  
Carbon Dioxide ◽  
Carbonic Anhydrase ◽  
Renal Handling ◽  
Dissolved Carbon ◽  
Multiple Indicator Dilution ◽  
Excretion Pattern ◽  
Dissolved Carbon Dioxide ◽  
Early Peak ◽  
Anesthetized Dogs ◽  
Multiple Indicator

The multiple-indicator-dilution technique has been applied to a study of the permeability of proximal and distal portions of the nephrons to dissolved carbon dioxide and bicarbonate ion in anesthetized dogs. Under control conditions with mannitol loading, the excreted carbon dioxide appears considerably earlier than the simultaneously injected creatinine whether dissolved CO2 or bicarbonate ion is injected. After inhibition of carbonic anhydrase by acetazolamide, there is relatively little effect on the excretion pattern of dissolved CO2. However, the excretion pattern of bicarbonate ion becomes nearly parallel to that of creatinine: the early peak disappears. On the basis of these results, it is concluded that the distal portions of the nephrons are permeable to dissolved CO2 but impermeable to bicarbonate ion and that, under control conditions, carbonic anhydrase serves to establish a catalytically mediated diffusion exchange for the transfer of CO2 derived from bicarbonate ion. Similar conclusions may apply to the proximal portions of the nephrons. On taking into account other data, it appears that the collecting ducts are impermeable to dissolved carbon dioxide. Carbon dioxide produced by decarboxylation of pyruvate has excretion patterns similar to those obtained for dissolved carbon dioxide. It is concluded that the decarboxylation product is dissolved CO2 and not bicarbonate ion.

CARDIORENAL EFFECTS OF LARGE INFUSIONS OF DEXTRAN IN DOGS

1954 ◽  
Vol 32 (5) ◽  
pp. 559-566 ◽  
Author(s):  
C. W. Gowdey ◽  
I. E. Young
Keyword(s):  
Cardiac Output ◽  
Peripheral Resistance ◽  
The Body ◽  
Arterial Blood ◽  
High Output Heart Failure ◽  
Mean Pressure ◽  
Anesthetized Dogs ◽  
The Right ◽  
Dextran Solution ◽  
High Output

The production of hypervolemic dilution anemia in intact, anesthetized dogs by the continuous intravenous infusion of 6% dextran solution caused large increases in the cardiac output and urine flow. No consistent changes were observed in pulse rate or arterial blood pressure. The right auricular mean pressure usually increased early in the infusion, but later there was no consistent relation between right auricular pressure and cardiac output. The total peripheral resistance, glomerular filtration rate, and renal blood flow decreased. With infusion volumes exceeding 10% of the body weight, acute high-output heart failure occurred. The observed hemodilution was consistently greater than that expected from the volume of the infusion, because the dextran solution was, presumably, hypertonic.

Carotid sinus and blood pressure control during hindlimb and forelimb contractions

1985 ◽  
Vol 248 (5) ◽  
pp. H688-H694
Author(s):  
O. Beaty
Keyword(s):  
Blood Pressure ◽  
Skeletal Muscle ◽  
Carotid Sinus ◽  
Pressure Control ◽  
Muscle Contractions ◽  
Arterial Blood ◽  
Afferent Information ◽  
Anesthetized Dogs ◽  
The Right

Arterial blood pressure (ABP) regulation during exercise involves in part medullary interaction of afferent information from contracting skeletal muscles and the major baroreceptors. This study examined in chloralose-anesthetized dogs the role of the carotid sinus baroreceptors in modulating reflex changes in ABP, nonexercising hindlimb skeletal muscle vascular resistance, and heart rate (HR) evoked by two separately contracting (4, 16, and 48 Hz) groups of skeletal muscle, the right hindlimb and forelimb. When arterial and cardiopulmonary baroreceptor afferent information was interrupted, hindlimb contractions evoked a greater augmentation of ABP (16 and 48 Hz) and no further increase in nonexercising hindlimb perfusion pressure (HLPP). Forelimb contractions, which in the presence of baroreceptors had not affected ABP (4 and 16 Hz), now reduced it profoundly. Nonexercising HLPP, which increased independently of contraction frequency, now was decreased by 4 Hz, not affected by 16 Hz, and increased by 48 Hz. The increase in HR was abolished. Increasing carotid sinus pressure to 220 mmHg in vagotomized dogs abolished the reflex changes evoked by hindlimb skeletal muscle contractions. However, forelimb contractions continued to decrease ABP. Nonexercising HLPP and HR did not change from the precontraction values. These data indicate that the carotid sinus baroreceptor could buffer completely those changes in the selected cardiovascular variables evoked by hindlimb but not forelimb skeletal muscle contractions. Thus the role of the carotid sinus baroreceptors in controlling ABP during exercise depends on the group of skeletal muscle initiating the somatic afferent signal and its influence on the contraction-induced distribution of the efferent signals.

Impact of Dursban and Abate on Microbial Numbers and Some Chemical Properties of Standing Ponds

1975 ◽  
Vol 10 (1) ◽  
pp. 33-41 ◽  
Author(s):  
J. Butcher ◽  
M. Boyer ◽  
CD. Fowle
Keyword(s):  
Carbon Dioxide ◽  
Active Ingredient ◽  
Algal Blooms ◽  
Chemical Properties ◽  
Total Carbon ◽  
Dissolved Carbon ◽  
Photosynthetic Productivity ◽  
Dissolved Carbon Dioxide ◽  
Microbial Numbers

Abstract Eleven small ponds, lined with polyethylene, were used to assess the consequences of applications of *DursbanR at 0.004, 0.030, 0.100 and 1.000 ppm and AbateR at 0.025 and 0.100 ppm active ingredient. The treated ponds showed a more pronounced long-term increase in pH and dissolved oxygen and decreasing total and dissolved carbon dioxide in comparison with untreated ponds. Algal blooms were of longer duration in treated ponds than in controls. Total photosynthetic productivity was higher in treated ponds but bacterial numbers did not change significantly. Photosynthetic productivity was estimated by following the changes in total carbon dioxide.

Strategies and adaptations to aquatic life at high altitude

2017 ◽  
Author(s):  
Dean Jacobsen ◽  
Olivier Dangles
Keyword(s):  
High Altitude ◽  
Environmental Conditions ◽  
Low Temperatures ◽  
Cold Adaptation ◽  
Inorganic Carbon ◽  
Direct Result ◽  
Aquatic Life ◽  
Dissolved Carbon ◽  
Dissolved Carbon Dioxide ◽  
Regulatory Capacity

Chapter 5 is focused on how organisms cope with the environmental conditions that are a direct result of high altitude. Organisms reveal a number of fascinating ways of dealing with a life at high altitude; for example, avoidance and pigmentation as protection against damaging high levels of ultraviolet radiation, accumulation of antifreeze proteins, and metabolic cold adaptation among species encountering low temperatures with the risk of freezing, oxy-regulatory capacity in animals due to low availability of oxygen, and root uptake from the sediment of inorganic carbon by plants living in waters poor in dissolved carbon dioxide. These and more adaptations are carefully described through a number of examples from famous flagship species in addition to the less well-known ones. Harsh environmental conditions work as an environmental filter that only allows the well-adapted species to slip through to colonize high altitude waters.

scholarly journals A METHOD TO DETERMINE THE PERIPHERAL ARTERIAL BLOOD PRESSURE IN THE MOUSE

1941 ◽  
Vol 74 (1) ◽  
pp. 29-40 ◽  
Author(s):  
Philip D. McMaster
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Arterial Blood Pressure ◽  
Close Agreement ◽  
Carotid Arteries ◽  
Systolic Pressure ◽  
Arterial Blood ◽  
Relative Transparency ◽  
Direct Measurements ◽  
Peripheral Arterial

Advantage has been taken of the relative transparency of the claw of the mouse to devise a method, here described, to measure the blood pressure in the animal's leg. Direct measurements of the systolic blood pressure from the carotid arteries of anesthetized mice have also been made. Simultaneous blood pressure readings by both these methods applied to the same animal showed close agreement. The systolic pressure ranged from 60 to 126 mm. Hg, according to the conditions.

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