STUDIES ON THERMOGENESIS IN COLD-ACCLIMATED BIRDS

1963 ◽  
Vol 41 (1) ◽  
pp. 2215-2220 ◽  
Author(s):  
R. R. J. Chaffee ◽  
W. W. Mayhew ◽  
M. Drebin ◽  
Y. Cassuto
Keyword(s):  
Oxygen Consumption ◽  
Cytochrome C ◽  
Liver Enzyme ◽  
Intravenous Injection ◽  
Pyridine Nucleotide ◽  
Small Rodents ◽  
Organ Weights ◽  
Enzyme Systems ◽  
And Control ◽  
Shivering Thermogenesis

Effects on oxygen consumption of continuous intravenous injection of various doses of L-noradrenaline were measured in anesthetized chickens acclimated to 1 °C for 3 months, and in controls. No effects were produced in either and it is concluded that noradrenaline is not a calorigenic mediator in cold-acclimated chickens. Liver succinoxidase and liver microsomal pyridine nucleotide-cytochrome c reductases of cold-acclimated and control sparrows were assayed, and there were no cold-induced differences. Since small cold-acclimated mammals show elevation of these liver enzyme systems, the findings indicate that the chemical basis of non-shivering thermogenesis (if this phenomenon is present at all) may involve different mechanisms in birds and mammals. Organ weights were measured, and it was found that in the sparrow, as in small rodents, the kidney and heart become enlarged in response to cold, perhaps indicating a convergent adaptation in these two diverse homoeotherms. Changes in the thickness and changes in color of the pectoral muscles which were observed in the cold-acclimated sparrows are discussed in relation to their possible roles in shivering thermogenesis.

STUDIES ON THERMOGENESIS IN COLD-ACCLIMATED BIRDS

1963 ◽  
Vol 41 (11) ◽  
pp. 2215-2220 ◽  
Author(s):  
R. R. J. Chaffee ◽  
W. W. Mayhew ◽  
M. Drebin ◽  
Y. Cassuto
Keyword(s):  
Oxygen Consumption ◽  
Cytochrome C ◽  
Liver Enzyme ◽  
Intravenous Injection ◽  
Pyridine Nucleotide ◽  
Small Rodents ◽  
Organ Weights ◽  
Enzyme Systems ◽  
And Control ◽  
Shivering Thermogenesis

Effects on oxygen consumption of continuous intravenous injection of various doses of L-noradrenaline were measured in anesthetized chickens acclimated to 1 °C for 3 months, and in controls. No effects were produced in either and it is concluded that noradrenaline is not a calorigenic mediator in cold-acclimated chickens. Liver succinoxidase and liver microsomal pyridine nucleotide-cytochrome c reductases of cold-acclimated and control sparrows were assayed, and there were no cold-induced differences. Since small cold-acclimated mammals show elevation of these liver enzyme systems, the findings indicate that the chemical basis of non-shivering thermogenesis (if this phenomenon is present at all) may involve different mechanisms in birds and mammals. Organ weights were measured, and it was found that in the sparrow, as in small rodents, the kidney and heart become enlarged in response to cold, perhaps indicating a convergent adaptation in these two diverse homoeotherms. Changes in the thickness and changes in color of the pectoral muscles which were observed in the cold-acclimated sparrows are discussed in relation to their possible roles in shivering thermogenesis.

THE INFLUENCE OF 17α-METHYL-19-NORTESTOSTERONE (M. N. T.) ON THE METABOLISM OF CORTISOL

1962 ◽  
Vol 39 (1) ◽  
pp. 22-31 ◽  
Author(s):  
A. Vermeulen ◽  
J. Ferin
Keyword(s):  
Urinary Excretion ◽  
Liver Enzyme ◽  
Chromatographic Analysis ◽  
Inactivation Rate ◽  
Chromatographic Study ◽  
List Type ◽  
Cortisol Metabolism ◽  
Enzyme Systems ◽  
Corticosterone Metabolites ◽  
Cortisol Metabolites

ABSTRACT The effect of prolonged 17α-methyl-nortestosterone (M. N. T.) administration on cortisol metabolism was studied in several patients. 1. A decreased urinary excretion of 17-hydroxycorticosteroids occurred regularly. 2. Chromatographic analysis of the urinary corticoids revealed that the decreased urinary excretion involved exclusively cortisol metabolites, whereas corticosterone metabolites were excreted at normal levels. This chromatographic study moreover showed an impairment in the conjugation of tetrahydrocorticoids. 3. Studies with 4-14C-cortisol in MNT treated patients showed increased transcortin levels, a normal cortisol pool, a reduced cortisol inactivation rate and a decreased cortisol production. 4. From these results it is concluded that the decreased 17-hydroxycorticoid excretion reflects a decreased cortisol production, at least partly secondary to a reduced cortisol-inactivation rate, which itself must be attributable either to an inhibition or a defect in the liver enzyme systems concerned in corticoid-inactivation.

scholarly journals Origin and Control of Chemoselectivity in Cytochrome c Catalyzed Carbene Transfer into Si–H and N–H bonds

2021 ◽  
Author(s):  
Marc Garcia-Borràs ◽  
S. B. Jennifer Kan ◽  
Russell D. Lewis ◽  
Allison Tang ◽  
Gonzalo Jimenez-Osés ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Carbene Transfer ◽  
And Control

Fever and thermogenesis in response to bacterial endotoxin involve macrophage-dependent mechanisms in rats

1993 ◽  
Vol 265 (5) ◽  
pp. R1179-R1183 ◽  
Author(s):  
R. H. Derijk ◽  
P. J. Strijbos ◽  
N. van Rooijen ◽  
N. J. Rothwell ◽  
F. Berkenbosch
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Intravenous Injection ◽  
Immune Cells ◽  
Interleukin 1 ◽  
Important Mediator ◽  
Selective Elimination ◽  
Colonic Temperature ◽  
Higher Doses ◽  
Intact Rats

Increases in thermogenesis and body temperature (fever) frequently accompany infection or injury and are thought to be mediated by endogenous pyrogens (e.g. cytokines), which are released from activated immune cells such as macrophages. Therefore, we have investigated the effect of selective elimination of peripheral macrophages on the changes in oxygen consumption (VO2) and colonic temperature in response to bacterial lipopolysaccharide (LPS) in the rat. Peripheral macrophages were depleted by intravenous injection of liposomes containing the drug dichloromethylene diphosphonate (Cl2MDP). Resting oxygen consumption and colonic temperatures were not affected by macrophage elimination. In intact rats, peripheral injection of LPS (0.1-0.5 mg/kg) elicited an increase in colonic temperature and in oxygen consumption that declined at higher doses (2.5 mg/kg). The pyrogenic and thermogenic responses to LPS were significantly attenuated in rats in which peripheral macrophages were eliminated. Previously, we have reported that elimination of macrophages blunts the plasma interleukin-1 (IL-1) response to LPS. Here we show that elimination of macrophages does not affect the increase in plasma IL-6 concentrations in response to LPS. These data indicate that the pyrogenic and thermogenic responses to LPS are at least in part dependent on mechanisms involving peripheral macrophages, and that peripherally produced IL-1 rather than IL-6 may be an important mediator of the changes in oxygen consumption and colonic temperature in response to LPS.

scholarly journals The effect of cytochrome C on the oxygen consumption of tissues of normal and CO-poisoned animals

1960 ◽  
Vol 152 (3) ◽  
pp. 482-486 ◽  
Author(s):  
J. S. Dutkiewicz ◽  
B. Gwózdź ◽  
K. Spett ◽  
Fr. M. Spioch
Keyword(s):  
Oxygen Consumption ◽  
Cytochrome C

Electron Transport and Coupled Energy Generation in Pseudomonas saccharophila

1971 ◽  
Vol 49 (11) ◽  
pp. 1175-1182 ◽  
Author(s):  
M. Ishaque ◽  
A. Donawa ◽  
M. I. H. Aleem
Keyword(s):  
Oxygen Consumption ◽  
Electron Transport ◽  
Cytochrome C ◽  
Atp Synthesis ◽  
Succinate Oxidation ◽  
Atp Formation ◽  
Low Concentrations ◽  
Oxidase Enzyme ◽  
Succinate Oxidase ◽  
Pseudomonas Saccharophila

The respiratory chain system of heterotrophically grown Pseudomonas saccharophila contained cytochromes of the b, c, a, and o types and also the NADH and succinate oxidase enzyme systems. Cell-free extracts catalyzed phosphorylation coupled to the oxidation of NADH, succinate, and ascorbate (plus cytochrome c). The P/O ratios were in the range of 1.00 for generated NADH, 0.29 for added NADH, 0.50 for succinate, and 0.25 for ascorbate (plus cytochrome c).The oxidative phosphorylation was uncoupled by 2,4-dinitrophenol, 2,6-dibromophenol, pentachlorophenol, m-chlorocarbonyl cyanide phenylhydrazone, and dicumarol without any inhibition of oxygen consumption. Phosphorylation coupled to NADH oxidation was completely inhibited by the flavoprotein inhibitors such as rotenone, amytal, and atabrine; these inhibitors had no effect, however, on the ATP synthesis associated with succinate oxidation. Antimycin A or 2-n-nonyl-4-hydroxyquinoline-N-oxide as well as cyanide or azide at low concentrations completely inhibited the phosphate esterification coupled to the oxidation of NADH or succinate, but had little or no effect on the oxygen consumption. Relatively higher concentrations of oligomycin were required for a complete inhibition of the electron-transport-linked ATP formation.

scholarly journals Mechanical Ventilation Preserves Diaphragm Mitochondrial Function in a Rat Sepsis Model

2020 ◽  
Author(s):  
Pierre Eyenga ◽  
Damien Roussel ◽  
Benjamin Rey ◽  
Patrice Ndille ◽  
Loic Teulier ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Oxygen Consumption ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Oxidase Activity ◽  
Ros Generation ◽  
Mitochondrial Oxygen Consumption ◽  
Atp Production ◽  
Mitochondrial Ros ◽  
Mda Content

Abstract Background: To describe the effect of mechanical ventilation on diaphragm mitochondrial oxygen consumption, ATP production, reactive oxygen species (ROS) generation, and cytochrome-c oxidase activity and content, and their relationship to diaphragm strength in an experimental model of sepsis.Methods: A cecal ligation and puncture (CLP) protocol was performed in 12 rats while 12 controls underwent sham-operation. Half of the rats in each group were paralyzed and mechanically ventilated. We performed blood gas analysis and lactic acid assays 6 hours after surgery. Afterwards, we measured diaphragm strength and mitochondrial oxygen consumption, ATP and ROS generation, and cytochrome-c oxidase activity. We also measured malondialdehyde (MDA) content as an index of lipid peroxidation, and mRNA expression of the pro-inflammatory interleukin-1β (IL-1β) in diaphragms.Results: CLP rats showed severe hypotension, metabolic acidosis, and upregulation of diaphragm IL-1β mRNA expression. Compared to sham controls, spontaneously breathing CLP rats showed lower diaphragm force and increased susceptibility to fatigue, along with depressed mitochondrial oxygen consumption and ATP production and cytochrome-c oxidase activity. These rats also showed increased mitochondrial ROS generation and MDA content. Mechanical ventilation markedly restored mitochondrial oxygen consumption and ATP production in CLP rats; lowered mitochondrial ROS production by the complex 3; and preserved cytochrome-c oxidase activity.Conclusion: In an experimental model of sepsis, early initiation of mechanical ventilation restores diaphragm mitochondrial function.

Cytochrome aa3 in facultatively aerobic and hyperthermophilic archaeon Pyrobaculum oguniense

2005 ◽  
Vol 51 (8) ◽  
pp. 621-627 ◽  
Author(s):  
Takuro Nunoura ◽  
Yoshihiko Sako ◽  
Takayoshi Wakagi ◽  
Aritsune Uchida
Keyword(s):  
Oxygen Consumption ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Gene Product ◽  
Respiratory Chain ◽  
Oxidase Activity ◽  
Terminal Oxidase ◽  
Hyperthermophilic Archaeon ◽  
Consumption Activity ◽  
Copper Oxidase

We partially purified and characterized the cytochrome aa3 from the facultatively aerobic and hyperthermophilic archaeon Pyrobaculum oguniense. This cytochrome aa3 showed oxygen consumption activity with N, N, N′, N′-tetramethyl-1,4-phenylenediamine and ascorbate as substrates, and also displayed bovine cytochrome c oxidase activity. These enzymatic activities of cytochrome aa3 were inhibited by cyanide and azide. This cytochrome contained heme As, but not typical heme A. An analysis of trypsin-digested fragments indicated that 1 subunit of this cytochrome was identical to the gene product of subunit I of the SoxM-type heme – copper oxidase (poxC). This is the first report of a terminal oxidase in hyperthermophilic crenarchaeon belonging to the order Thermoproteales.Key words: aerobic respiratory chain, terminal oxidase, Archaea, hyperthermophile, Pyrobaculum.

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