Increased monoamine oxidase activity and imidazoline binding sites in insulin-resistant adipocytes from obese Zucker rats

Figure 6 Tissue-selective larger imidazoline binding site density in the white adipocytes from obese rats when compared to lean littermates. Crude membranes were prepared from adipocytes isolated from white subcutaneous fat depots, the liver, interscapular brown adipose tissue, and soleus muscle, and incubated for 45 min with 20 nmol/L³H-2-(2-benzofuranyl)-2-imidazoline (³H-BFI), before separation by vacuum filtration as indicated in Methods. Only the specific binding of ³H-BFI, i.e., displaceable by 100 µmol/L cirazoline, is shown. For each tissue, there was one determination of specific binding per rat, calculated by the difference between total and non-specific binding. Results are the mean ± SEM of the number of rats indicated above each column (open for lean, shaded for obese rats). Significantly different from corresponding value in lean at: ^cP < 0.001.