Pharmacological and physiological properties of benzodiazepine binding sites in rodent brown adipose tissue

1984 ◽  
Vol 77 (2) ◽  
pp. 339-343 ◽  
Author(s):  
James D. Hirsch
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Binding Sites ◽  
Physiological Properties ◽  
Brown Adipose ◽  
Benzodiazepine Binding ◽  
Benzodiazepine Binding Sites

Rapid changes in number of GDP binding sites on brown adipose tissue mitochondria

1986 ◽  
Vol 251 (2) ◽  
pp. E192-E195
Author(s):  
A. G. Swick ◽  
R. W. Swick
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Binding Sites ◽  
Uncoupling Protein ◽  
Membrane Integrity ◽  
Binding Activity ◽  
Bat Mitochondria ◽  
Brown Adipose ◽  
Rapid Changes ◽  
Binding To Mitochondria

GDP binding to brown adipose tissue (BAT) mitochondria increased more than twofold in 20 min when rats were moved from 27 to 4 degrees C. When animals housed at 4 degrees C for 2 h were returned to 27 degrees C, GDP binding decreased sharply in 20 min and returned to control levels in 2 h. These results are consistent with a rapid unmasking and remasking of GDP binding sites. GDP binding to mitochondria from warm and acutely cold treated rats was not modified by prior swelling, by freeze-thawing, nor by sonication of the mitochondria before assay. GDP-inhibitable proton conductance, as measured by passive swelling, was unaffected by this brief exposure to cold but more than doubled in rats kept at 4 degrees C for 10 days. We hypothesize that the rate of GDP-inhibitable swelling may be a reflection of uncoupling protein concentration in the BAT mitochondria, whereas physiological thermogenic activity is more appropriately indicated by GDP binding. The alterations in binding activity appear not to be due to changes in the mitochondrial membrane integrity.

scholarly journals Evidence for decreased GDP binding to brown-adipose-tissue mitochondria of obese Zucker (fa/fa) rats in the very first days of life

1984 ◽  
Vol 221 (1) ◽  
pp. 241-245 ◽  
Author(s):  
R Bazin ◽  
D Eteve ◽  
M Lavau
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Binding Sites ◽  
Scatchard Analysis ◽  
Zucker Rat ◽  
Large Decrease ◽  
Sequential Order ◽  
Lean Control ◽  
Brown Adipose ◽  
Obese Zucker Rat

GDP binding to brown-adipose-tissue mitochondria of obese Zucker-rat (fa/fa) pups aged 2-14 days was significantly less than in lean control rats. Scatchard analysis in 10-day-old pups suggests that there was a large decrease in GDP-binding sites. However, a significant increase in fat content in brown adipose tissue of 2-day-old pre-obese pups raised the question of the sequential order and causal relationship between these two derangements.

Identification of two mitochondrial GDP-binding sites in rat brown adipose tissue

1983 ◽  
Vol 3 (7) ◽  
pp. 589-598 ◽  
Author(s):  
K. R. Bryant ◽  
N. J. Rothwell ◽  
M. J. Stock ◽  
D. Stribling
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Binding Sites ◽  
Dissociation Constants ◽  
Mitochondrial Protein ◽  
Scatchard Analysis ◽  
Nucleotide Binding Sites ◽  
Guanosine Diphosphate ◽  
Brown Adipose ◽  
Number Of Binding Sites

Scatchard analysis of specific guanosine-diphosphate-([3H]GDP-) binding to rat brown-adipose-tissue mitochondria revealed two distinct binding sites with apparent dissociation constants (Kd) of approximately 0.05 and 2.0 μM. Binding to both sites was insensitive to atractyloside. Reducing the pH of the binding medium from 7.1 to 6.6 caused marked reductions in the Kd of both sites, but at pH 7.6, the dissociation constants were increased about 3-fold. Acute treatment of rats with noradrenaline, 1 h before sacrifice, increased the maximum number of binding sites (Bmax, pmol/rng mitochondrial protein) of both sites and also increased the dissociation constants. The Bmax of the lower-affinity site was elevated in rats exposed to 5°C or fed a palatable cafeteria diet for 10 d, compared to control animals, with the greater changes occurring in the cold-adapted group. The high-affinity site was unaltered by cold adaptation or cafeteria feeding. These results indicate the presence of two distinct nucleotide-binding sites in brown-fat mitochondria, both of which may be involved in thermogenesis.

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