Hibernation, temperature and rates of oxidative phosphorylation by heart mitochondria

1960 ◽  
Vol 198 (2) ◽  
pp. 463-466 ◽  
Author(s):  
Frank E. South
Keyword(s):  
Oxygen Consumption ◽  
Oxidative Phosphorylation ◽  
Incubation Temperature ◽  
Regression Line ◽  
Vertical Displacement ◽  
Heart Mitochondria ◽  
Oxidative Enzymes ◽  
Effect Of Temperature ◽  
The Difference

The effect of temperature on rates of oxidative phosphorylation (pyruvate substrate) by heart mitochondria obtained from hibernating hamsters, control hamsters and rats was studied. Apparent energies of activation ( Ea) determined between 5° and 24°C were, respectively, 20.4, 20.8 and 28.3 Kcal. for the rates of oxygen consumption and 20.6, 21.4 and 29.5 Kcal. for the rates of phosphorylation. The difference between the rats and either group of hamsters were significant statistically. The slope of the regression line fitted to the data obtained from hibernating animals did not differ significantly from that of the control hamsters. However, a parallel vertical displacement of the lines indicated a probable increase in these oxidative enzymes upon preparation for, or during, hibernation. No significant alterations in the efficiency of oxidative phosphorylation with variations in the incubation temperature were noted in any of the preparations.

Incubation temperature, energy expenditure and hatchling size in the green turtle (Chelonia mydas), a species with temperature-sensitive sex determination

2001 ◽  
Vol 49 (4) ◽  
pp. 389 ◽  
Author(s):  
David T. Booth ◽  
Katherine Astill
Keyword(s):  
Oxygen Consumption ◽  
Production Cost ◽  
Incubation Temperature ◽  
Chelonia Mydas ◽  
Temperature Sensitive ◽  
Barrier Reef ◽  
Body Dimensions ◽  
Green Turtles ◽  
The Difference ◽  
Hatchling Size

Eggs from the Heron Island, Great Barrier Reef, nesting population of green turtles (Chelonia mydas) were incubated at all-male-determining (26˚C) and all-female-determining (30˚C) temperatures. Oxygen consumption and embryonic growth were monitored throughout incubation, and hatchling masses and body dimensions were measured from both temperatures. Eggs hatched after 79 and 53 days incubation at 26˚C and 30˚C respectively. Oxygen consumption at both temperatures increased to a peak several days before hatching, a pattern typical of turtle embryos, and the rate of oxygen was higher at 30˚C than 26˚C. The total amount of energy consumed during incubation, and hatchling dimensions, were similar at both temperatures, but hatchlings from 26˚C had larger mass, larger yolk-free mass and smaller residual yolks than hatchlings from 30˚C. Because of the difference in mass of hatchlings, hatchlings from 30˚C had a higher production cost.

scholarly journals Effect of conditioning and physiology hyperthermia on canine skeletal muscle mitochondrial oxygen consumption

2021 ◽  
Author(s):  
Michael S. Davis ◽  
Montana R. Barrett
Keyword(s):  
Skeletal Muscle ◽  
Oxidative Phosphorylation ◽  
Incubation Temperature ◽  
Adenine Nucleotide ◽  
Uncoupling Protein ◽  
Mechanistic Explanation ◽  
Effect Of Temperature ◽  
Sled Dogs ◽  
Before And After ◽  
Exercise Induced

Exercise often causes skeletal muscle hyperthermia, likely resulting in decreased efficiency of mitochondrial respiration. We hypothesized that athletic conditioning would improve mitochondrial tolerance to hyperthermia. Skeletal muscle biopsies were obtained from 6 Alaskan sled dogs under light general anesthesia before and after a full season of conditioning and racing, and respiration of permeabilized muscle fibers was measured at 38, 40, 42, and 44°C. There was no effect of temperature on phosphorylating respiration, and athletic conditioning increased maximal phosphorylating respiration by 19%. Leak respiration increased and calculated efficiency of oxidative phosphorylation decreased with increasing incubation temperature, and athletic conditioning resulted in higher leak respiration and lower calculated oxidative phosphorylation efficiency at all temperatures. Conditioning increased skeletal muscle expression of putative mitochondrial leak pathways adenine nucleotide transporter 1 and uncoupling protein 3, both of which were correlated with the magnitude of leak respiration. We conclude that athletic conditioning in elite canine endurance athletes results in increased capacity for mitochondrial proton leak that potentially reduces maximal mitochondrial membrane potential during periods of high oxidative phosphorylation. This effect may provide a mechanistic explanation for previously-reported decreases in exercise-induced muscle damage in well-conditioned subjects.

Incubation of eggs of the Australian broad-shelled turtle, Chelodina expansa (Testudinata : Chelidae), at different temperatures: effects on pattern of oxygen consumption and hatchling morphology

2000 ◽  
Vol 48 (4) ◽  
pp. 369 ◽  
Author(s):  
David T. Booth
Keyword(s):  
Oxygen Consumption ◽  
Energy Expenditure ◽  
Production Efficiency ◽  
Incubation Temperature ◽  
Effect Of Temperature ◽  
Temperature Dependent ◽  
Rate Of Increase ◽  
Different Temperatures ◽  
Rate Of Oxygen Consumption ◽  
Incubation Temperatures

Incubation temperature influences embryonic development and the morphology of resultant hatchlings in many species of turtle but few studies have addressed its effect on oxygen consumption and total embryonic energy expenditure. Eggs of the Australian broad-shelled river turtle, Chelodina expansa, were incubated at constant temperatures of 24˚C and 28˚C to determine the effect of temperature on oxygen consumption, embryonic energy expenditure and hatchling morphology. All embryos at both incubation temperatures experienced a period of developmental diapause immediately after oviposition. Once this initial diapause was broken, embryos underwent a further period of developmental arrest when the embryo was still very small and had minimal oxygen consumption (<20 µL h–1). However, once rapid embryonic growth started, development appeared to be continuous. Rate of increase and peak rate of oxygen consumption were temperature dependent, both being highest at 28˚C. Net production efficiency (total oxygen consumed during incubation divided by yolk-free hatchling mass) was 120 mL O2 g–1 at 24˚C and 111 mL O2g–1 at 28˚C. Hatchling mass and yolk-free hatchling mass were independent of incubation temperature, but hatchlings from 28˚C had larger residual yolks and smaller head widths than hatchlings from 24˚C.

scholarly journals The Respiration of some Planktonic copepods II. The Effect Of Temperature

1953 ◽  
Vol 31 (3) ◽  
pp. 447-460 ◽  
Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont
Keyword(s):  
Respiratory Rate ◽  
The Body ◽  
The Other ◽  
Effect Of Temperature ◽  
Acartia Clausi ◽  
Temora Longicornis ◽  
Different Temperatures ◽  
Planktonic Copepods ◽  
The Difference ◽  
The Relationship

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.

scholarly journals Contributions of source population and incubation temperature to phenotypic variation of hatchling Chinese skinks

2020 ◽  
Author(s):  
Hong-Liang Lu ◽  
Yan-Fu Qu ◽  
Hong Li ◽  
Xiang Ji
Keyword(s):  
Body Mass ◽  
Phenotypic Variation ◽  
Incubation Temperature ◽  
Tail Length ◽  
Population Variation ◽  
Phenotypic Traits ◽  
Source Population ◽  
Relative Importance ◽  
The Difference ◽  
Hatchling Size

Abstract Phenotypic plasticity and local adaptation are viewed as the main factors that result in between-population variation in phenotypic traits, but contributions of these factors to phenotypic variation vary between traits and between species and have only been explored in a few species of reptiles. Here, we incubated eggs of the Chinese skink (Plestiodon chinensis) from 7 geographically separated populations in Southeast China at 3 constant temperatures (24, 28, and 32 °C) to evaluate the combined effects of clutch origin, source population, and incubation temperature on hatchling traits. The relative importance of these factors varied between traits. Nearly all examined hatchling traits, including body mass, snout–vent length (SVL), tail length, head size, limb length, tympanum diameter, and locomotor speed, varied among populations and were affected by incubation temperature. Measures for hatchling size (body mass and SVL) varied considerably among clutches. Source population explained much of the variation in hatchling body mass, whereas incubation temperature explained much of the variation in other examined traits. Our results indicate that between-population variation in hatchling traits of P. chinensis likely reflects the difference in natural incubation conditions and genetic divergence.

scholarly journals Upregulation of COX4-2 via HIF-1α in Mitochondrial COX4-1 Deficiency

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 452
Author(s):  
Liza Douiev ◽  
Chaya Miller ◽  
Shmuel Ruppo ◽  
Hadar Benyamini ◽  
Bassam Abu-Libdeh ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Oxidative Phosphorylation ◽  
Nuclear Localization ◽  
Target Genes ◽  
Compensatory Mechanism ◽  
Terminal Electron Acceptor ◽  
Human Foreskin Fibroblasts ◽  
Mitochondrial Respiratory Complex ◽  
Mrna Transcripts ◽  
Oxphos System

Cytochrome-c-oxidase (COX) subunit 4 (COX4) plays important roles in the function, assembly and regulation of COX (mitochondrial respiratory complex 4), the terminal electron acceptor of the oxidative phosphorylation (OXPHOS) system. The principal COX4 isoform, COX4-1, is expressed in all tissues, whereas COX4-2 is mainly expressed in the lungs, or under hypoxia and other stress conditions. We have previously described a patient with a COX4-1 defect with a relatively mild presentation compared to other primary COX deficiencies, and hypothesized that this could be the result of a compensatory upregulation of COX4-2. To this end, COX4-1 was downregulated by shRNAs in human foreskin fibroblasts (HFF) and compared to the patient’s cells. COX4-1, COX4-2 and HIF-1α were detected by immunocytochemistry. The mRNA transcripts of both COX4 isoforms and HIF-1 target genes were quantified by RT-qPCR. COX activity and OXPHOS function were measured by enzymatic and oxygen consumption assays, respectively. Pathways were analyzed by CEL-Seq2 and by RT-qPCR. We demonstrated elevated COX4-2 levels in the COX4-1-deficient cells, with a concomitant HIF-1α stabilization, nuclear localization and upregulation of the hypoxia and glycolysis pathways. We suggest that COX4-2 and HIF-1α are upregulated also in normoxia as a compensatory mechanism in COX4-1 deficiency.

scholarly journals Dextran strongly increases the Michaelis constants of oxidative phosphorylation and of mitochondrial creatine kinase in heart mitochondria

1998 ◽  
Vol 254 (1) ◽  
pp. 172-180 ◽  
Author(s):  
Frank Norbert Gellerich ◽  
Fanny Dorine Laterveer ◽  
Bernard Korzeniewski ◽  
Stephan Zierz ◽  
Klaas Nicolay
Keyword(s):  
Creatine Kinase ◽  
Oxidative Phosphorylation ◽  
Heart Mitochondria ◽  
Mitochondrial Creatine Kinase ◽  
Michaelis Constants

scholarly journals Functional Disorders of the Oxidative Phosphorylation System in the Heart Mitochondria of Mice with Juvenile Visceral Steatosis

2003 ◽  
Vol 26 (3) ◽  
pp. 289-294 ◽  
Author(s):  
Midori Suenaga ◽  
Naokatu Arakaki ◽  
Kayoko Morokami ◽  
Toshiki Himeda ◽  
Hirofumi Shibata ◽  
...  
Keyword(s):  
Oxidative Phosphorylation ◽  
Heart Mitochondria ◽  
Functional Disorders ◽  
Oxidative Phosphorylation System

Abstract 104: Effects of Pinacidil and Ca 2 + on Sodium-loaded Rat Heart Mitochondria

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Sergey M Korotkov ◽  
Vladimir P Nesterov ◽  
Irina V Brailovskaya ◽  
Larisa V Emelyanova ◽  
Svetlana A Konovalova ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Rat Heart ◽  
Mitochondrial Membrane ◽  
Mitochondrial Permeability Transition ◽  
Ischemia Reperfusion ◽  
Potassium Acetate ◽  
Heart Mitochondria ◽  
Inner Mitochondrial Membrane ◽  
Rat Heart Mitochondria ◽  
Acetate Medium

Deterioration of the contractile parameters of the heart muscle caused by ischemia and followed reperfusion is known as the main postoperative complication which is related to Ca 2+ and Na + overload in cardiomyocytes and mitochondria. Pinacidil reduced the overload in ischemia/reperfusion experiments. The mechanism of this phenomenon is still not clear. We hypothesized that increased ion permeability of the inner mitochondrial membrane (IMM) followed drop of electrochemical potential (ΔΨ mito ) can reduce the calcium. The aim of the study was to elucidate the effect of pinacidil (100 μM) and Ca 2+ (100 μM ) on swelling, oxygen consumption and ΔΨ mito of isolated sodium-loaded rat heart mitochondria (RHM(Na)) energized glutamate and malate. Pinacidil significantly enchanced the permeability of IMM to protons in ammonium nitrate medium. Also increased swelling of RHM(Na) energized with substrates in potassium acetate medium revealed that pinacidil increased potassium transport into matrix. Pinacidil stimulated oxygen consumption of RHM(Na) in State 4 and detained Ca 2+ -induced dissipation of ΔΨ mito . Under condition of Ca 2+ and Na + overload simulating ischemia/reperfusion, RHM(Na) oxygen consumption was not affected with pinacidil in State 3 and in the presence of 2,4-dinitrophenol. Cyclosporin A and ADP, the inhibitors of mitochondrial permeability transition pore (MPTP), markedly decreased Ca 2+ - induced swelling of RHM(Na) in nitrate ammonium or potassium acetate medium in the presence of pinacidil. Carboxyatractyloside, an inhibitor of cytosolic side-specific adenine nucleotide translocase, eliminated a pinacidil-stimulated oxygen consumption of succinate-energized RHMNa in State 4 regardless of the presence of Ca 2+ . Pinacidil was also concluded to accelerat potassium flux into energized RHM(Na) and promot MPTP opening in the low conduction state. Based on our data we suggested that the effect of pharmacological preconditioning induced by pinacidil could be due to it’s direct effect on mitochondria which is connected with above stimulation of the potassium permeability of the inner mitochondrial membrane and following reduce of the ΔΨ mito that thus prevent calcium overload of cardiomyocytes after ischemia/reperfusion in turn.

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