Changes induced by cold adaptation in the brown adipose tissue from several species of rodents, with special reference to the mitochondrial components

1979 ◽  
Vol 57 (11) ◽  
pp. 1262-1266 ◽  
Author(s):  
D. Ricquier ◽  
G. Mory ◽  
P. Hemon
Keyword(s):  
Molecular Weight ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Guinea Pigs ◽  
Cold Adaptation ◽  
Phospholipid Fatty Acid ◽  
Phospholipid Fatty Acid Composition ◽  
Brown Adipose ◽  
Total Tissue ◽  
Brown Fat Mitochondria

(1) The effects of cold adaptation upon the brown adipose tissue have been studied in rats, hamsters, mice, and guinea pigs.(2) Striking effects were found for total tissue as well as at the mitochondrial level, e.g., increases in protein and phospholipid contents, changes in phospholipid fatty acid composition (a decrease in the percentage of palmitic and palmitoleic acids and an increase in stearic and linoleic acids), and a change in the mitochondrial polypeptide composition (a marked increase in a 32 000 molecular weight polypeptide, except for hamsters).(3) In situations where animals exhibit a greatly enhanced capacity for nonshivering thermo-genesis (cold adaptation for rats, mice, and guinea pigs, birth for guinea pigs, and hibernation ability for hamsters, dormice, and garden dormice), brown fat mitochondria are characterized by the occurrence of large amounts of the 32 000 molecular weight polypeptide characteristic of these mitochondria.

scholarly journals Biogenesis of thermogenic mitochondria in brown adipose tissue of Djungarian hamsters during cold adaptation

1996 ◽  
Vol 316 (2) ◽  
pp. 607-613 ◽  
Author(s):  
Martin KLINGENSPOR ◽  
Marc IVEMEYER ◽  
Herbert WIESINGER ◽  
Kirsten HAAS ◽  
Gerhard HELDMAIER ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Cold Exposure ◽  
Cold Adaptation ◽  
Uncoupling Protein ◽  
Respiratory Chain Complexes ◽  
Mitochondrial Transcription Factor ◽  
Chain Complexes ◽  
Brown Adipose ◽  
Total Tissue

After cold exposure, cytochrome c oxidase (COX) activity increased about 2.5-fold within 2 weeks in the brown adipose tissue (BAT) of Djungarian hamsters. The mRNAs for COX subunits I and III and the 12 S rRNA, encoded on mitochondrial DNA (mtDNA), as well as mRNAs for COX subunits IV, Va and mitochondrial transcription factor A, encoded in the nucleus, were unchanged when expressed per unit of total tissue RNA. However, since total tissue RNA doubled per BAT depot, while total DNA remained unchanged, the actual levels of these transcripts were increased within BAT cells. In contrast, the abundance of mRNA for uncoupling protein was increased 10-fold, indicating specific activation of this gene. In addition, the maximal rate of protein synthesis analysed in a faithful in organello system was increased 2.5-fold in mitochondria isolated from BAT after 7 days of cold exposure. We conclude from these data that the biogenesis of thermogenic mitochondria in BAT following cold adaptation is achieved by increasing the overall capacity for synthesis of mitochondrial proteins in both compartments, by increasing their mRNAs as well as the ribosomes needed for their translation. In addition, the translational rate for COX subunits as well as all other proteins encoded on mtDNA is increased. Thus the pool of subunits encoded on mtDNA required for assembly of respiratory chain complexes is provided. By comparison with other models of increased mitochondrial biogenesis, we propose that thyroid hormone (generated within BAT cells by 5´-deiodinase, and induced upon sympathetic stimulation), which is a well known regulator of the biogenesis of mitochondria in many tissues, is also the major effector of these adaptive changes in BAT.

The Effects of Thyroxine and Isopropylnoradrenaline on Cytochrome Oxidase Activity in Brown Adipose Tissue

1973 ◽  
Vol 51 (10) ◽  
pp. 751-758 ◽  
Author(s):  
H. M. C. Heick ◽  
C. Vachon ◽  
Mary Ann Kallai ◽  
Nicole Bégin-Heick ◽  
J. LeBlanc
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Protein Content ◽  
Cytochrome Oxidase ◽  
Cold Adaptation ◽  
Metabolic Response ◽  
Mitochondrial Enzymes ◽  
Cold Adapted ◽  
Brown Adipose ◽  
Hormonal Treatments

Groups of animals were treated with injections of isopropylnoradrenaline, thyroxine, or both hormones together. The effects of these hormonal treatments on the size, protein content, and level of some mitochondrial enzymes, in particular the cytochrome oxidase, were determined and compared to the effect on these parameters produced by cold adaptation. The changes observed were correlated with the resistance of the animals to cold stress and with their metabolic response to injections of isopropylnoradrenaline. All treatments increased the size of the brown adipose tissue. Whereas thyroxine had little effect on the protein content and cytochrome oxidase, both isopropylnoradrenaline and cold adaptation produced increases in these parameters. It appears that the isopropylnoradrenaline-treated animals mimic more closely the cold-adapted animals than do those with thyroxine treatment. However, the isopropylnoradrenaline-treated animals are not as resistant to cold as the cold-adapted animals.

Evidence that fasting can induce a selective loss of uncoupling protein from brown adipose tissue mitochondria of mice

1986 ◽  
Vol 6 (9) ◽  
pp. 805-810 ◽  
Author(s):  
P. Trayhurn ◽  
G. Jennings
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Cytochrome Oxidase ◽  
Oxidase Activity ◽  
Uncoupling Protein ◽  
Cytochrome Oxidase Activity ◽  
Selective Loss ◽  
Brown Adipose ◽  
Fasting And Refeeding ◽  
Total Tissue

The effects of fasting and refeeding on the concentration of uncoupling protein in brown adipose tissue mitochondria have been investigated in mice. Fasting mice for 48 h led to a large decrease in the total cytochrome oxidase activity of the interscapular brown fat pad. Mitochondrial GDP binding and the specific mitochondrial concentration of uncoupling protein also fell on fasting. After 24 h refeeding both GDP binding and the mitochondrial concentration of uncoupling protein were normalized, but there was no alteration in the total tissue cytochrome oxidase activity. Fasting appears to induce a selective loss of uncoupling protein from brown adipose tissue mitochondria, which is rapidly reversible on refeeding.

Polypeptide turnover in brown adipose tissue mitochondria during acclimation of rats to cold

1980 ◽  
Vol 58 (4) ◽  
pp. 336-344 ◽  
Author(s):  
Jean Himms-Hagen ◽  
Elizabeth Dittmar ◽  
Gloria Zaror-Behrens
Keyword(s):  
Molecular Weight ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Initial Phase ◽  
Mitochondrial Membrane ◽  
High Capacity ◽  
Proton Conductance ◽  
General Increase ◽  
Brown Adipose ◽  
Selective Increase

During the initial phase of cold-induced growth of brown adipose tissue in rats there is a selective increase in the incorporation of infused [3H]phenylalanine into mitochondrial membrane polypeptides of molecular weight 25 000–35 000. This is interpreted as a selective increase in the synthesis of a 32 000 polypeptide, of which the proportion is known to increase in brown adipose tissue mitochondria when the tissue has a high capacity for thermogenesis, as in the cold-acclimated rat. This polypeptide is known to be associated with the thermogenic proton conductance pathway. A simultaneous selective decrease in degradation or the formation from larger mitochondrial membrane polypeptides may also occur. In fully cold-acclimated rats, in which a new steady state is reached, there is a general increase in turnover of all mitochondrial membrane polypeptides but no marked selective changes in pattern of incorporation of radioactive amino acid or in rates of disappearance of radioactivity from groups of polypeptides. Isolated brown adipose tissue mitochondria incorporate [3H]phenylalanine principally into polypeptides of molecular weight 25 000–35 000. No change in the pattern of incorporation occurred in mitochondria isolated from brown adipose tissue of cold-exposed (2 weeks) rats. On the basis of these and preceding results it is concluded that the cold-induced change in mitochondrial composition in brown adipose tissue, which occurs at the same time as tissue and mitochondrial growth, is brought about by selective changes in cytosolic protein synthesis and possibly also by selectively altered degradation or conversion of mitochondrial polypeptides.

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