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

Figure 5 Tyramine oxidation in adipocytes from obese and lean Zucker rats. Undamaged adipocytes isolated from visceral white adipose tissue of lean (open columns) and obese (dark columns) rats were incubated in the presence of 1 mmol/L ¹⁴C-tyramine for 45 min at 37 °C. Total oxidation was measured without any inhibitor, while the oxidation that resisted to 1 mmol/L semicarbazide was due to monoamine oxidase, and the oxidation resistant to 1 mmol/L pargyline was semicarbazide-sensitive amine oxidase-dependent. The velocities of oxidation are expressed as as nmoles of radiolabeled tyramine oxidation products generated per min and per mg of proteins. Each column is the mean ± SEM of eight determinations for lean and nine determinations for obese male rats. Significantly different from lean at: ^aP < 0.05; ^bP < 0.01.