Role of membrane charge and semiquinone structure on oxygen consumption rates

Author(s):  
Antonio E. Alegría ◽  
Lizmarie Rivera ◽  
Emelyn Cordones ◽  
Veronica Castro ◽  
Pedro Sanchez-Cruz
2015 ◽  
Vol 63 (51) ◽  
pp. 10928-10937 ◽  
Author(s):  
Vicente Ferreira ◽  
Vanesa Carrascon ◽  
Mónica Bueno ◽  
Maurizio Ugliano ◽  
Purificación Fernandez-Zurbano

2008 ◽  
Vol 5 (suppl_2) ◽  
Author(s):  
Joe Dragavon ◽  
Tim Molter ◽  
Cody Young ◽  
Tim Strovas ◽  
Sarah McQuaide ◽  
...  

The development of a cellular isolation system (CIS) that enables the monitoring of single-cell oxygen consumption rates in real time is presented. The CIS was developed through a multidisciplinary effort within the Microscale Life Sciences Center (MLSC) at the University of Washington. The system comprises arrays of microwells containing Pt-porphyrin-embedded polystyrene microspheres as the reporter chemistry, a lid actuator system and a gated intensified imaging camera, all mounted on a temperature-stabilized confocal microscope platform. Oxygen consumption determination experiments were performed on RAW264.7 mouse macrophage cells as proof of principle. Repeatable and consistent measurements indicate that the oxygen measurements did not adversely affect the physiological state of the cells measured. The observation of physiological rates in real time allows studies of cell-to-cell heterogeneity in oxygen consumption rate to be performed. Such studies have implications in understanding the role of mitochondrial function in the progression of inflammatory-based diseases, and in diagnosing and treating such diseases.


1995 ◽  
Vol 268 (3) ◽  
pp. E433-E438 ◽  
Author(s):  
M. D. Jensen ◽  
C. M. Johnson ◽  
P. E. Cryer ◽  
M. J. Murray

To determine the relative contribution of splanchnic and leg tissues to postprandial thermogenesis, systemic and regional oxygen consumption rates were measured in nine women and eight men before and for 6 h after the consumption of a mixed meal that provided one-third of the daily energy needs. In women, the increase in splanchnic oxygen uptake accounted for 63 +/- 12% of the postprandial increase in oxygen consumption, whereas in men it accounted for 35 +/- 14% (P = not significant between women and men). Leg oxygen uptake accounted for 11 +/- 4 and 10 +/- 3% of the increase in postprandial oxygen consumption in women and men, respectively. The combined data suggest that approximately 48% of postprandial thermogenesis over 6 h occurs in splanchnic tissues, whereas 30-35% occurs in skeletal muscle. Thus the increase in oxygen consumption after a mixed meal is primarily localized to splanchnic tissues, and major reductions in postprandial thermogenesis are unlikely to be attributable solely to abnormalities of skeletal muscle metabolism.


2021 ◽  
Vol 22 (5) ◽  
pp. 2578
Author(s):  
Trim Lajqi ◽  
Christian Marx ◽  
Hannes Hudalla ◽  
Fabienne Haas ◽  
Silke Große ◽  
...  

Microglia, the innate immune cells of the CNS, exhibit long-term response changes indicative of innate immune memory (IIM). Our previous studies revealed IIM patterns of microglia with opposing immune phenotypes: trained immunity after a low dose and immune tolerance after a high dose challenge with pathogen-associated molecular patterns (PAMP). Compelling evidence shows that innate immune cells adopt features of IIM via immunometabolic control. However, immunometabolic reprogramming involved in the regulation of IIM in microglia has not been fully addressed. Here, we evaluated the impact of dose-dependent microglial priming with ultra-low (ULP, 1 fg/mL) and high (HP, 100 ng/mL) lipopolysaccharide (LPS) doses on immunometabolic rewiring. Furthermore, we addressed the role of PI3Kγ on immunometabolic control using naïve primary microglia derived from newborn wild-type mice, PI3Kγ-deficient mice and mice carrying a targeted mutation causing loss of lipid kinase activity. We found that ULP-induced IIM triggered an enhancement of oxygen consumption and ATP production. In contrast, HP was followed by suppressed oxygen consumption and glycolytic activity indicative of immune tolerance. PI3Kγ inhibited glycolysis due to modulation of cAMP-dependent pathways. However, no impact of specific PI3Kγ signaling on immunometabolic rewiring due to dose-dependent LPS priming was detected. In conclusion, immunometabolic reprogramming of microglia is involved in IIM in a dose-dependent manner via the glycolytic pathway, oxygen consumption and ATP production: ULP (ultra-low-dose priming) increases it, while HP reduces it.


2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Beth N. Orcutt ◽  
C. Geoffrey Wheat ◽  
Olivier Rouxel ◽  
Samuel Hulme ◽  
Katrina J. Edwards ◽  
...  

1958 ◽  
Vol 35 (2) ◽  
pp. 383-395
Author(s):  
R. W. EDWARDS

1. The oxygen consumption rates of 3rd- and 4th-instar larvae of Chironomus riparius have been measured at 10 and 20° C. using a constant-volume respirometer. 2. The oxygen consumption is approximately proportional to the 0.7 power of the dry weight: it is not proportional to the estimated surface area. 3. This relationship between oxygen consumption and dry weight is the same at 10 and at 20° C.. 4. The rate of oxygen consumption at 20° C. is greater than at 10° C. by a factor of 2.6. 5. During growth the percentage of dry matter of 4th-instar larvae increases from 10 to 16 and the specific gravity from 1.030 to 1.043. 6. The change in the dry weight/wet weight ratio during the 4 larval instar supports the theory of heterauxesis. 7. At 20° C., ‘summer’ larvae respire faster than ‘winter’ larvae.


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