| Abstract: | 3H]Diazepam and 3H] Ro5 -4864 were used as ligands to identify and characterize peripheral-type benzodiazepine binding sites in mouse and rat brown adipose tissue (BAT) membranes. 3H]Diazepam and 3H] Ro5 -4864 binding sites in BAT are pharmacologically similar to peripheral-type benzodiazepine binding sites in other tissues. Stimulators of central-type benzodiazepine receptors had no effect on or inhibited ligand binding to BAT membranes. Brown adipose tissue benzodiazepine binding sites are highly localized to mitochondria-containing subcellular fractions. These binding sites decrease with age in BAT from Fischer 344 rats. Stimulation of BAT thermogenesis in mice with 1-norepinephrine led to a decrease in 3H] Ro5 -4864 binding in the tissue. |
