scholarly journals Effects of Bicarbonate on the Respiration and Glycolytic Activity of Boar Spermatozoa

1978 ◽  
Vol 31 (4) ◽  
pp. 385 ◽  
Author(s):  
RN Murdoch ◽  
WD Davis

The metabolism of washed boar spermatozoa was studied in the presence and absence of low levels of bicarbonate (6 mM) and carbon dioxide (2 %). Bicarbonate stimulated the oxygen consumption of the spermatozoa but had no apparent effect on glycolysis. The stimulatory effect of bicarbonate on respiration depended on the presence of a utilizable exogenous energy source such as glucose, fructose, lactate, or pyruvate and no stimulation occurred when no substrate was added or when acetate was used as substrate. The response of the spermatozoa to bicarbonate also depended on the presence of adequate concentrations of potassium (5 mM) and to a lesser extent magnesium (1 mM).

1962 ◽  
Vol 40 (5) ◽  
pp. 817-862 ◽  
Author(s):  
Richard L. Saunders

Respiratory volumes, percentage utilizations of oxygen, and rates of oxygen consumption were measured in non-swimming and swimming white suckers, brown bullheads, and carp under various ambient levels of oxygen and carbon dioxide. Up to 85% of the oxygen in the inspired water is removed by quietly breathing fish. Generally, high respiratory volumes are associated with low percentage utilizations of oxygen and vice versa. At high respiratory volumes carp remove about twice as much oxygen from the inspired water as do suckers and bullheads. Respiratory volumes are increased by as much as 30 times over the volume for quiet respiration by low levels of oxygen or high levels of carbon dioxide. Respiratory volumes of swimming fish are greater than those of non-swimming, rested fish in air-saturated water but they are not as high as those of non-swimming fish exposed to low ambient oxygen levels.The effects of moderate increases in ambient carbon dioxide on non-swimming fish may be temporary only. If the rise in the pCO2 is slight to moderate, the percentage utilizations of oxygen at given respiratory volumes are at first depressed but may return, after 3 to 5 hours, to the levels they held before the pCO2 was raised. Actively swimming fish respond to any increase in the pCO2 by permanently increased breathing rates and decreased percentage utilizations of oxygen and rates of oxygen consumption.The number of respiratory units or lamellae per millimeter of gill filament in suckers, bullheads, and carp weighing 200 g are about 14, 10, and 20 respectively, but the total numbers and areas of lamellae are such that total gill areas are nearly identical among these three species.


Author(s):  
Grażyna Mazurkiewicz-Boroń ◽  
Teresa Bednarz ◽  
Elżbieta Wilk-Woźniak

Microbial efficiency in a meromictic reservoirIndices of microbial efficiency (expressed as oxygen consumption and carbon dioxide release) were determined in the water column of the meromictic Piaseczno Reservoir (in an opencast sulphur mine), which is rich in sulphur compounds. Phytoplankton abundances were low in both the mixolimnion (up to 15 m depth) and monimolimnion (below 15 m depth). In summer and winter, carbon dioxide release was 3-fold and 5-fold higher, respectively, in the monimolimnion than in the mixolimnion. Laboratory enrichments of the sulphur substrate of the water resulted in a decrease in oxygen consumption rate of by about 42% in mixolimnion samples, and in the carbon dioxide release rate by about 69% in monimolimnion samples. Water temperature, pH and bivalent ion contents were of major importance in shaping the microbial metabolic efficiency in the mixolimnion, whilst in the monimolimnion these relationships were not evident.


1992 ◽  
Vol 70 (3) ◽  
pp. 408-411 ◽  
Author(s):  
Peter B. Frappell ◽  
Andrea Dotta ◽  
Jacopo P. Mortola

Aerobic metabolism (oxygen consumption, [Formula: see text], and carbon dioxide production, [Formula: see text]) has been measured in newborn rats at 2 days of age during normoxia, 30 min of hyperoxia (100% O2) and an additional 30 min of recovery in normoxia at ambient temperatures of 35 °C (thermoneutrality) or 30 °C. In normoxia, at 30 °C [Formula: see text] was higher than at 35 °C. With hyperoxia, [Formula: see text] increased in all cases, but more so at 30 °C (+20%) than at 35 °C (+9%). Upon return to normoxia, metabolism readily returned to the prehyperoxic value. The results support the concept that the normoxic metabolic rate of the newborn can be limited by the availability of oxygen. At temperatures below thermoneutrality the higher metabolic needs aggravate the limitation in oxygen availability, and the positive effects of hyperoxia on [Formula: see text] are therefore more apparent.Key words: neonatal respiration, oxygen consumption, thermoregulation.


PEDIATRICS ◽  
1964 ◽  
Vol 33 (1) ◽  
pp. 75-82
Author(s):  
Forrest H. Adams ◽  
Tetsuro Fujiwara ◽  
Robert Spears ◽  
Joan Hodgman

Thirty-four measurements of oxygen consumption, carbon dioxide production, respiratory quotient, and rectal temperature were made on 22 premature infants with ages ranging from 2½ hours to 18 days. The studies were conducted at 32-34°C utilizing an open circuit apparatus and a specially designed climatized chamber. Oxygen consumption and carbon dioxide production were lowest in the first 12 hours and increased thereafter. The rate of increase in O2 consumption was greater than that of CO2 production, with a consequent fall in respiratory quotient during the first 76 hours of life. A reverse relation of O2 consumption and CO2 production was found following the 4th day of life with a consequent rise in respiratory quotient. There was a close correlation between O2 consumption and rectal temperature regardless of age. A respiratory quotient below the value of 0.707 for fat metabolism was observed in 7 premature infants with ages ranging from 24 to 76 hours.


1958 ◽  
Vol 193 (3) ◽  
pp. 495-498 ◽  
Author(s):  
Ruth McClintock ◽  
Nathan Lifson

Measurements of oxygen consumption and carbon dioxide production were made by the Haldane open circuit method on hereditarily obese mice and littermate controls, and the energy expenditures were estimated. Studies were made on mice for short periods under ‘basal’ conditions, and for periods of approximately a day with the mice fasted and confined, fasted and relatively unconfined, and fed and unconfined. The total energy expenditures of fed and unconfined obese mice were found to be higher than those of nonobese littermate controls by virtue of a) increased ‘basal metabolism’, b) greater energy expenditure associated with feeding, and possibly c) larger energy output for activity despite reduced voluntary movement. The values obtained for total metabolism confirm those previously determined by an isotope method for measuring CO2 output.


Metabolism ◽  
2015 ◽  
Vol 64 (3) ◽  
pp. 416-427 ◽  
Author(s):  
Madlyn I. Frisard ◽  
Yaru Wu ◽  
Ryan P. McMillan ◽  
Kevin A. Voelker ◽  
Kristin A. Wahlberg ◽  
...  

1972 ◽  
Vol 52 (1) ◽  
pp. 57-63
Author(s):  
L. M. SANFORD ◽  
G. J. KING

Boar spermatozoa were diluted in Ringer’s fructose or sulfate buffer and incubated aerobically for 4 hr at 37 C (a) in the presence of potassium hydroxide (KOH), hyamine hydroxide, or diethanolamine (DEA) absorbents, and (b) in 1, 2, or 3% atmospheric levels of carbon dioxide. Oxygen uptake by boar spermatozoa was enhanced by the presence of DEA compared with KOH and hyamine hydroxide. Incubation with DEA resulted in increased spermatozoan livability, more desirable cell motion, and smaller increases in buffer pH. Oxygen uptake by boar spermatozoa was optimum with 1 or 2% carbon dioxide, depending upon which buffer cells were diluted in. Levels of 2 and 3% carbon dioxide maintained oxygen uptake and livability of boar spermatozoa during later stages of the incubation period equally as well as 1% carbon dioxide. As the level of atmospheric carbon dioxide increased, buffer pH remained closer to the initial value.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 7-7
Author(s):  
Quentin Fovez ◽  
Bruno Quesnel ◽  
William Laine ◽  
Raeeka Khamari ◽  
Celine Berthon ◽  
...  

Introduction The persistence of leukemic cells after treatment limits the effectiveness of anticancer drugs and is the cause of relapse in patients with acute myeloid leukemia (AML). After exposure to chemotherapeutic drugs, the survival of leukemic cells is mainly supported by mitochondrial energy metabolism. Several preclinical studies have shown that the combination of mitochondrial oxidative phosphorylation inhibitors with various anticancer treatments constitutes an effective therapeutic combination in vitro to eradicate the surviving leukemic cells. Evaluating the mitochondrial bioenergetic activity of blasts from AML patients could therefore provide predictive information on treatment response. The basal oxygen consumption of cells varies according to hematopoietic differentiation and depends on the energy needs in the in vitro condition of measurement. But it is necessary to treat the cells with uncoupling agents (eg FCCP) to assess the maximum activity that the respiratory chain could reach to respond to energy stress. Then, the switch from a basal level of oxygen consumption to a maximum level defines the mitochondrial spare reserve capacity (SRC). In this study, we propose to determine whether spare reserve capacity of blasts is a potential biomarker of AML aggressiveness in patients and to characterize the biochemical processes involved in the control of SRC in leukemic cells. Results Using the XFe24 Seahorse fluorometric oximeter, we first determined the mitochondrial oxygen consumption and glycolytic activity in hematopoietic cells (monocytes, lymphocytes, dendritic cells) of healthy donors, in AML patient blasts at diagnosis or at relapse and in AML cell lines (HL-60, MOLM-13, THP-1, KG1, OCI-AML3, MV-4-11, U-937). All measures have been assessed from freshly collected samples of peripheral blood and of bone marrow. As expected, AMLs are characterized by low oxidative phosphorylation activity compared to normal hematopoietic cells. From all the OXPHOS values obtained we defined a SRC threshold above which the SRC is considered high. This threshold has been set at a capacity to increase basal respiration by 250%. From patients blasts, we have therefore defined two groups characterized by high (n=14) or low (n=21) mitochondrial spare reserve capacity. Blasts with high SRC exhibit high glycolytic activity suggesting a link between spare reserve capacity and glucose metabolism. Using U-13C6 glucose and pharmacological inhibitors, we have demonstrated that the utilization of the mitochondrial spare reserve capacity of leukemic cells is supported through glycolysis and that mitochondrial oxidation of pyruvate is a key element for SRC recruitment. Mitochondrial pyruvate carrier inhibitors (as UK-5099) or gene silencing of BRP44 abolish the SRC of leukemic cells highlighting the importance of pyruvate oxidation to increase oxygen consumption. Since high mutation rate is recognized as an unfavorable prognostic factor in AML, we have also sequenced 45 commonly genes mutated in AMLs characterized by high or low SRC blasts. Interestingly, DNA sequencing analysis showed that AML with low SRC blasts have a higher mutation rate than high SRC blasts and also exhibited exclusive mutations such as ASXL1 (25%), IDH2 (25%), NPM1 (25%), IDH1 (13%), JAK2 (13%) and SF3B1 (13%). Conclusion Currently, most of the clinical biomarkers used to predict AML aggressiveness are based on DNA analysis, but the emergence of mutations is not always associated with phenotypic changes. This study shows that the mitochondrial spare reserve capacity of blasts represents a new functional biomarker based on the assessment of the energetic phenotype and could help the clinicians to determine the prognosis of AML. Moreover we have showed that altering pyruvate metabolism highly decrease spare reserve capacity of blasts and then could be evaluated as metabolic strategies to improve the therapeutic response in patients with AML. Disclosures Kluza: Daiichi-Sankyo: Research Funding.


1970 ◽  
Vol 48 (16) ◽  
pp. 2542-2548 ◽  
Author(s):  
V. G. Sorensen ◽  
V. M. Bhale ◽  
K. J. McCallum ◽  
R. J. Woods

Hydrogen bromide, glycolic acid, and carbon dioxide have been identified as products of the γ-radiolysis of aqueous 2,2,2-tribromoethanol solutions. The effect of oxygen, tribromoethanol concentration, and dose rate upon the yields of bromide ion and acid have been determined, and partial radiolysis mechanisms are proposed for reaction in the presence and absence of oxygen. Dibromoacetaldehyde, reported to be a product of the photochemical decomposition of tribromoethanol solutions, was not detected in the radiolysis experiments or in tribromoethanol solutions exposed to sunlight.


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