Increased GDP binding and thermogenic activity in brown adipose tissue mitochondria during arousal of the hibernating garden dormouse (Eliomys quercinus L.).
1. The thermogenic activity of brown adipose tissue in hibernating garden dormice during hypothermic torpor and at different states of arousal were studied. High levels of GDP binding were observed on isolated brown fat mitochondria, indicating that the thermogenic proton conductance pathway is very active in brown fat during arousal. 2. In order to investigate this phenomenon, the uncoupling protein was assessed by immunological assay and the mRNA for UCP was analysed. 3. Animals during arousal exhibited neither increase in UCPmRNA nor an increase in UCP. 4. Our results suggest that during the rewarming of garden dormice there is an acute unmasking of GDP binding sites on the protein.
Laboratoire des Régulations des Métabolismes et Nutrition Université Paul Sabatier, Toulouse, France.
R
R
Martins
C
C
Atgie
L
L
Gineste
M
M
Nibbelink
L
L
Ambid
D
D
Ricquier
D002001:Adipose Tissue, Brown / Q000502:physiology*; D000818:Animals; D001143:Arousal / Q000502:physiology*; D015152:Blotting, Northern; D001833:Body Temperature Regulation / Q000502:physiology*; D001835:Body Weight / Q000502:physiology; D006153:Guanosine Diphosphate / Q000378:metabolism*; D006605:Hibernation / Q000502:physiology*; D015151:Immunoblotting; D008928:Mitochondria / Q000502:physiology; D011485:Protein Binding; D012377:Rodentia / Q000502:physiology*
D006153:Guanosine Diphosphate