Figure 5.

β-AR antagonists decrease lipid accumulation in hepatocytes from old rats. Hepatocytes from young (6 months old) and old (24 months old) rats (n=3 in each group) were treated with the selective β₁-AR antagonist CGP 20712 (CGP, 1 μM) or the β₂-AR antagonist ICI 118, 551 (ICI, 100 nM) for 72 h. The cells were then fixed and stained with ORO to measure cellular lipid accumulation, as described in Materials and methods. Results indicate a reduction in lipid accumulation by 40 and 30% in cells isolated from old rats and treated with CGP and ICI, respectively, compared to vehicle-treated hepatocytes (control, C). No reduction in hepatocellular lipid accumulation was observed in cells isolated from young rats and treated with β-AR selective antagonists. Each experiment was performed in triplicate. Data are presented as mean values ±s.e.m. and expressed relative to control (100%). *P<0·003 vs C; ^¶P<0·06 vs C.