Effects of cold acclimation in dystrophic hamsters: reduction of heart necrosis

1986 ◽  
Vol 250 (2) ◽  
pp. R167-R174
Author(s):  
M. Desautels ◽  
R. A. Dulos
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Cold Acclimation ◽  
Ventricular Hypertrophy ◽  
Body Weight Gain ◽  
Calcium Content ◽  
Co2 Production ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose ◽  
Plasma Creatine Kinase

The effects of cold acclimation on brown adipose tissue, heart, and skeletal muscles were evaluated to assess if the increase in metabolic activity associated with chronic exposure to 4 degrees C had any influence on the progression of the syndrome in dystrophic hamsters. Body weight gain was much slower in dystrophic animals kept at 22 degrees C and was unaffected by cold acclimation. Rates of O2 consumption and CO2 production were similar in normal and dystrophic hamsters kept at 22 degrees C, and both were increased in cold-acclimated normal and dystrophic animals. The amount of interscapular brown adipose tissue was about one-half of normal in dystrophic hamsters kept at 22 degrees C. In response to cold acclimation, as in normal hamsters, brown adipose tissue of dystrophic hamsters grew and increased its thermogenin content by more than fourfold. However, the concentration of thermogenin in isolated mitochondria remained unchanged. Heart ventricular hypertrophy was also observed in both normal and dystrophic hamsters after cold acclimation. The number and extent of cardiac necrotic lesions were significantly reduced in cold-acclimated dystrophic animals when compared with age-matched dystrophic hamsters kept at 22 degrees C. Heart calcium content and plasma creatine kinase levels were also reduced in dystrophic hamsters after cold acclimation. However, in soleus muscles the prevalence of centronucleated fibers, an indirect cumulative index of necrosis, as well as the extent of tissue necrosis were not significantly reduced in cold-acclimated dystrophic animals. Thus cold acclimation of dystrophic hamsters appeared to reduce necrosis predominantly in the heart.

Lipid metabolism: Effects of immunosympathectomy and acclimation to cold

1968 ◽  
Vol 46 (3) ◽  
pp. 453-461 ◽  
Author(s):  
G. Steiner ◽  
E. Schönbaum ◽  
G. E. Johnson ◽  
E. A. Sellers
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Cold Acclimation ◽  
Relative Weight ◽  
Fat Pad ◽  
Liver Lipids ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose ◽  
Glucose Recovery ◽  
Intact Rats

The effects of immunosympathectomy and acclimation to cold on the incorporation of glucose-U-14C into lipids of the interscapular brown adipose tissue, epididymal fat pad, and liver of rats have been investigated. Acclimation to cold was associated with an increase in glucose recovered in the total lipids of brown adipose tissue. These changes in glucose recovery were the same in immunosympathectomized as in intact rats. The brown adipose tissue of the two groups of cold-acclimated rats differed, however, in that this tissue in the immunosympathectomized animals was larger and had more lipid. Suggestions are raised to explain these findings. Neither immunosympathectomy nor cold acclimation produced any changes in white adipose tissue. Immunosympathectomy did not alter the liver's handling of glucose. However, cold-acclimation was associated with an increase in the relative weight of the liver and a decrease in glucose recovery in liver lipids.

Effects of sucrose, caffeine, and cola beverages on obesity, cold resistance, and adipose tissue cellularity

1983 ◽  
Vol 244 (4) ◽  
pp. R500-R507 ◽  
Author(s):  
L. J. Bukowiecki ◽  
J. Lupien ◽  
N. Follea ◽  
L. Jahjah
Keyword(s):  
Adipose Tissue ◽  
Weight Gain ◽  
Brown Adipose Tissue ◽  
White Adipose Tissue ◽  
Cold Resistance ◽  
Body Weight Gain ◽  
Caffeine Intake ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose ◽  
Triglyceride Content

Rats consuming Coca-Cola and Purina chow ad libitum increased their total energy intake by 50% without excess weight gain. Their resistance to cold was markedly improved. These phenomena were characterized by significant increases in interscapular brown adipose tissue weight (IBAT) (91%), cellularity (59%), triglyceride content (52%), protein content (94%), and cytochrome oxidase activity (167%). In contrast, Coca-Cola consumption did not significantly affect the cellularity or triglyceride content of parametrial white adipose tissue (PWAT), although it slightly augmented PWAT weight. The effects of Coca-Cola on cold resistance, IBAT cellularity, and composition were entirely reproduced by sucrose, but not caffeine, consumption. Although caffeine also increased IBAT cellularity and composition, it significantly decreased the rate of body weight gain, PWAT weight, and adipocyte size. Moreover, it markedly inhibited adipocyte proliferation in PWAT thereby mimicking the effects of exercise training and food restriction (Bukowiecki et al., Am. J. Physiol. 239 (Endocrinol. Metab. 2): E422-E429, 1980). It is concluded a) that sucrose and Coca-Cola consumption improve the resistance of rats to cold, most probably by increasing brown adipose tissue cellularity, and b) that moderate caffeine intake might be useful for inhibiting proliferative activity in white adipose tissue, thereby preventing obesity.

scholarly journals Amino acid and glucose uptake by rat brown adipose tissue. Effect of cold-exposure and acclimation

1988 ◽  
Vol 252 (3) ◽  
pp. 843-849 ◽  
Author(s):  
F J López-Soriano ◽  
J A Fernández-López ◽  
T Mampel ◽  
F Villarroya ◽  
R Iglesias ◽  
...  
Keyword(s):  
Amino Acids ◽  
Adipose Tissue ◽  
Amino Acid ◽  
Brown Adipose Tissue ◽  
Glucose Uptake ◽  
Cold Acclimation ◽  
Cold Exposure ◽  
Acid Oxidation ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose

The net uptake/release of glucose, lactate and amino acids from the bloodstream by the interscapular brown adipose tissue of control, cold-exposed and cold-acclimated rats was estimated by measurement of arteriovenous differences in their concentrations. In the control animals amino acids contributed little to the overall energetic needs of the tissue; glucose uptake was more than compensated by lactate efflux. Cold-exposure resulted in an enhancement of amino acid utilization and of glucose uptake, with high lactate efflux. There was a net glycine and proline efflux that partly compensated the positive nitrogen balance of the tissue; amino acids accounted for about one-third of the energy supplied by glucose to the tissue. Cold-acclimation resulted in a very high increase in glucose uptake, with a parallel decrease in lactate efflux and amino acid consumption. Branched-chain amino acids, however, were more actively utilized. This was related with a much higher alanine efflux, in addition to that of glycine and proline. It is suggested that most of the glucose used during cold-exposure is returned to the bloodstream as lactate under conditions of active lipid utilization, amino acids contributing their skeletons largely in anaplerotic pathways. On the other hand, cold-acclimation resulted in an important enhancement of glucose utilization, with lowered amino acid oxidation. Amino acids are thus used as metabolic substrates by the brown adipose tissue of rats under conditions of relatively scarce substrate availability, but mainly as anaplerotic substrates, in parallel to glucose. Cold-acclimation results in a shift of the main substrates used in thermogenesis from lipid to glucose, with a much lower need for amino acids.

Brown adipose tissue hyperplasia: a fundamental mechanism of adaptation to cold and hyperphagia

1982 ◽  
Vol 242 (6) ◽  
pp. E353-E359 ◽  
Author(s):  
L. Bukowiecki ◽  
A. J. Collet ◽  
N. Follea ◽  
G. Guay ◽  
L. Jahjah
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Cold Acclimation ◽  
Cold Exposure ◽  
Interstitial Cells ◽  
Brown Adipocyte ◽  
Brown Adipocytes ◽  
Interscapular Brown Adipose Tissue ◽  
Blood Capillaries ◽  
Brown Adipose

Cold acclimation (4 degrees C) and "cafeteria diets" increased the thermic response of rats to catecholamines. This phenomenon was accompanied by six- to eightfold increases of interscapular brown adipose tissue (IBAT) weight, total tissue cytochrome oxidase activity, and total number of brown adipocytes. Quantitative radioautographic experiments using [3H]thymidine disclosed that cold exposure markedly enhanced the mitotic activity in blood capillaries and small-venule endothelial cells, adipose tissue interstitial cells, and preadipocytes rather than in fully differentiated brown adipocytes. IBAT mitotic index increased 70 times over control values after only 2 days of cold exposure. Thereafter, the proliferative activity progressively decreased. IBAT cell composition was modified during cold acclimation as the percentage of interstitial cells and preadipocytes increased over the other cellular types. Because brown adipose tissue is the principal site of norepinephrine-induced thermogenesis in homeothermal animals, it is suggested that brown adipocyte proliferation from precursor cells represents the fundamental phenomenon explaining the increased capacity of cold-acclimated animals to respond calorigenically to catecholamines.

Interscapular brown adipose tissue metabolic reprogramming during cold acclimation: Interplay of HIF-1α and AMPKα

2011 ◽  
Vol 1810 (12) ◽  
pp. 1252-1261 ◽  
Author(s):  
Milica Vucetic ◽  
Vesna Otasevic ◽  
Aleksandra Korac ◽  
Ana Stancic ◽  
Aleksandra Jankovic ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Cold Acclimation ◽  
Metabolic Reprogramming ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose
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