Time course of aerobic recovery after contraction of rabbit papillary muscle

1987 ◽  
Vol 253 (2) ◽  
pp. H325-H332 ◽  
Author(s):  
F. Mast ◽  
G. Elzinga
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Time Constant ◽  
Oxygen Consumption Rate ◽  
Time Course ◽  
Consumption Rate ◽  
Oxygen Storage ◽  
Measuring System ◽  
Measured Time ◽  
Isometric Twitch

The time course of oxygen uptake after isometric twitch contractions of isolated rabbit papillary muscles was determined at 20 degrees C by continuous polarographic measurement of the partial pressure of oxygen in a 219-microliters glass chamber in which the fluid circulated rapidly. The response time of the oxygen-measuring system was characterized by a delay of 1.1 s and a time constant of 2.1 s after that delay. Depending on the stimulation frequency (0.125–1.0 Hz) the total amount of oxygen uptake for 120 twitches varied from 5.3 to 32.7 nmol/mg dry wt, and the steady-state oxygen consumption rate varied from 0.4 to 8.5 nmol X min-1 X mg dry wt-1. On the basis of a diffusion model we eliminated the effect of oxygen storage on the measured time course of oxygen consumption to determine the mitochondrial kinetics. We found a time constant of an average 19–22 s of mitochondrial off kinetics. By use of this time constant for the change in oxygen consumption rate after contraction, it can be estimated that 9–10% of the oxygen required to restore ATP levels is already taken up by the mitochondria during the twitch.

THE IN VITRO ACTION OF ACTH ON THE OXYGEN CONSUMPTION OF SLICES OF CATTLE ADRENAL CORTEX

1953 ◽  
Vol 9 (4) ◽  
pp. 379-390 ◽  
Author(s):  
M. REISS ◽  
EVA BRUMMEL ◽  
I. D. K. HALKERSTON ◽  
F. E. BADRICK ◽  
M. FENWICK
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Linear Relationship ◽  
Adrenal Cortex ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Biological Assay ◽  
Percentage Increase ◽  
Small Doses

A technique for measuring the action of small doses of ACTH on the oxygen consumption of slices of cattle adrenal cortex is described. The oxygen consumption rate of such slices in vitro is increased by ACTH. A linear relationship between logarithm of the dose of ACTH and the percentage increase in the rate of oxygen uptake is obtained with this method, and its suitability for biological assay purposes has been investigated. The question of the specificity of this action of ACTH is discussed.

Quantifying Compound Aging Resistance at Service (Ambient) Temperatures

2009 ◽  
Vol 82 (1) ◽  
pp. 121-130
Author(s):  
Edward R. Terrill ◽  
James T. Lewis
Keyword(s):  
Oxygen Consumption ◽  
Service Life ◽  
Oxygen Uptake ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Tensile Elongation ◽  
Ambient Temperatures ◽  
Rubber Compounds ◽  
Consumption Rates ◽  
The Stability

Abstract Oxygen consumption rates were measured on natural rubber compounds with varying levels of a standard antioxidant package. The oxygen consumption rate measurements were performed at temperatures between 20 °C and 80 °C. The results elucidated the mechanism of antioxidants, including their pro-oxidant effects. The pro-oxidant effect dwindled with time. Integrated oxygen uptake results were calculated from repetitive oxygen consumption rate measurements. Integrated oxygen uptake time temperature master curves with empirical shift factors were combined with elongation-tobreak data to monitor the extent of aging. The stability of the compounds at service life temperatures could be quantified by combining the integrated oxygen uptake shift factors with the tensile elongation-to-break data; thereby to produce an elongation-to-break master curve at service life temperatures.

Microbial efficiency in a meromictic reservoir

2008 ◽  
Vol 37 (2) ◽  
Author(s):  
Grażyna Mazurkiewicz-Boroń ◽  
Teresa Bednarz ◽  
Elżbieta Wilk-Woźniak
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Release Rate ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Metabolic Efficiency ◽  
Sulphur Compounds ◽  
Carbon Dioxide Release ◽  
Microbial Efficiency ◽  
Ion Contents

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.

scholarly journals Correction: Paszkiewicz et al. A Peripheral CB1R Antagonist Increases Lipolysis, Oxygen Consumption Rate, and Markers of Beiging in 3T3-L1 Adipocytes Similar to RIM, Suggesting That Central Effects Can Be Avoided. Int. J. Mol. Sci. 2020, 21, 6639

2021 ◽  
Vol 22 (9) ◽  
pp. 4366
Author(s):  
Rebecca L. Paszkiewicz ◽  
Richard N. Bergman ◽  
Roberta S. Santos ◽  
Aaron P. Frank ◽  
Orison O. Woolcott ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Central Effects

The authors wish to make the following corrections to this paper [...]

scholarly journals Necrostatin-1 Supplementation to Islet Tissue Culture Enhances the In-Vitro Development and Graft Function of Young Porcine Islets

2021 ◽  
Vol 22 (16) ◽  
pp. 8367
Author(s):  
Hien Lau ◽  
Shiri Li ◽  
Nicole Corrales ◽  
Samuel Rodriguez ◽  
Mohammadreza Mohammadi ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Oxygen Consumption ◽  
Insulin Secretion ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
In Vitro Development ◽  
Porcine Islets ◽  
Vitro Development

Pre-weaned porcine islets (PPIs) represent an unlimited source for islet transplantation but are functionally immature. We previously showed that necrostatin-1 (Nec-1) immediately after islet isolation enhanced the in vitro development of PPIs. Here, we examined the impact of Nec-1 on the in vivo function of PPIs after transplantation in diabetic mice. PPIs were isolated from pancreata of 8–15-day-old, pre-weaned pigs and cultured in media alone, or supplemented with Nec-1 (100 µM) on day 0 or on day 3 of culture (n = 5 for each group). On day 7, islet recovery, viability, oxygen consumption rate, insulin content, cellular composition, insulin secretion capacity, and transplant outcomes were evaluated. While islet viability and oxygen consumption rate remained high throughout 7-day tissue culture, Nec-1 supplementation on day 3 significantly improved islet recovery, insulin content, endocrine composition, GLUT2 expression, differentiation potential, proliferation capacity of endocrine cells, and insulin secretion. Adding Nec-1 on day 3 of tissue culture enhanced the islet recovery, proportion of delta cells, beta-cell differentiation and proliferation, and stimulation index. In vivo, this leads to shorter times to normoglycemia, better glycemic control, and higher circulating insulin. Our findings identify the novel time-dependent effects of Nec-1 supplementation on porcine islet quantity and quality prior to transplantation.

Sign in / Sign up

Export Citation Format

Share Document