The Identification of the Component in the Inner Membrane of Brown Adipose Tissue Mitochondria Responsible for Regulating Energy Dissipation

1978 ◽  
pp. 89-93 ◽  
Author(s):  
David G. Nicholls ◽  
Vibeke S. M. Bernson ◽  
Gillian M. Heaton
Keyword(s):  
Adipose Tissue ◽  
Energy Dissipation ◽  
Brown Adipose Tissue ◽  
Inner Membrane ◽  
Brown Adipose

Inhibition by Oxytetracycline of the Development of the Enhanced Response to Noradrenaline in Cold-Acclimated Rats: A New Approach to the Study of Nonshivering Thermogenesis

1971 ◽  
Vol 49 (6) ◽  
pp. 545-553 ◽  
Author(s):  
Jean Himms–Hagen
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Cytochrome Oxidase ◽  
Oxidase Activity ◽  
Metabolic Response ◽  
Inner Membrane ◽  
Cytochrome Oxidase Activity ◽  
Mitochondrial Inner Membrane ◽  
Brown Adipose

The aim of these experiments was to depress the increased metabolic activity of the brown adipose tissue in the intact rat during acclimation to cold in order to elucidate further the possible thermogenic and endocrine functions of this tissue. The antibiotic oxytetracycline was administered twice daily for 2 weeks to rats living at 4 °C in an attempt to inhibit the proliferation of mitochondria and of mitochondrial inner membrane known to occur in the brown adipose tissue in response to cold; control rats received saline during the same period. Total cytochrome oxidase activity served as an index of the amount of mitochondrial inner membrane in brown adipose tissue, liver, and skeletal muscle. The development of an enhanced calorigenic response to intravenously infused noradrenaline served as an index of the extent of acclimation to cold.Treatment with oxytetracycline inhibited both the cold-induced increase in cytochrome oxidase activity in brown adipose tissue and the cold-induced development of an enhanced calorigenic response to noradrenaline in the intact rats; a direct correlation was noted between the amount of cytochrome oxidase in brown adipose tissue and the size of the metabolic response to noradrenaline of the intact animals. However, the amount of oxygen that could be consumed by the total cytochrome oxidase in the brown adipose tissue was itself too small to account for the increase in oxygen consumption by the rat. Treatment of the rats with oxytetracycline did not alter the cold-induced growth of brown adipose tissue (as judged by the increase in wet weight and the increase in total protein); it also did not alter the cytochrome oxidase activities of liver or skeletal muscle. The effect of oxytetracycline seems, therefore, to be fairly specific for the mitochondria of the most rapidly dividing tissue, the brown adipose tissue. The conclusion is drawn that a protein synthesized in the mitochondria of the brown adipose tissue in response to cold is essential for adaptation to cold.

Evidence for two distinct chloride uniport pathways in brown adipose tissue mitochondria

1989 ◽  
Vol 257 (6) ◽  
pp. C1142-C1148 ◽  
Author(s):  
P. Jezek ◽  
A. D. Beavis ◽  
D. J. Diresta ◽  
R. N. Cousino ◽  
K. D. Garlid
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Mitochondrial Swelling ◽  
Chloride Permeability ◽  
Inner Membrane ◽  
Anion Conductance ◽  
Conducting Pathway ◽  
Brown Adipose ◽  
The Matrix ◽  
Anion Uniport

Chloride permeability of the inner membrane of brown adipose tissue mitochondria was analyzed by monitoring mitochondrial swelling in KCl salts in the presence of K+ ionophores. The results indicate that the high anion conductance observed in these mitochondria is due to the presence of two separate pathways: 1) a Cl-conducting pathway that is inhibited by guanosine 5'-diphosphate (GDP) but neither by N,N'-dicyclohexylcarbodiimide (DCCD) nor by amphiphilic amines and that is found uniquely in brown adipose tissue mitochondria and 2) an inner membrane anion uniport channel that is inhibited both by DCCD and by amphiphilic amines but not by GDP and that is opened either by depletion of matrix Mg2+ or by alkalinization of the matrix.

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