Fig. 7.
Calorie restriction attenuates the age-related onset of IL-1β hyperresponsiveness. A: Effects of calorie restriction on GSH levels in hepatocytes. GSH levels in hepatocytes from aged (20 months) calorie-restricted (CR) or ad libitum-fed (AL) rats were measured using the Bioxytech® GSH/GSSG-412™ assay kit. Results are presented as nmol GSH/mg cellular protein and are means ± SD (n = 4). * P < 0.013. B: Effects of calorie restriction on NSMase activity in hepatocytes. NSMase activity in hepatocytes from aged (20 months) calorie-restricted (CR) or ad libitum-fed (AL) rats was measured as described. Results are presented as specific activity of NSMase (hydrolysis of picomoles of substrate per milligram of cellular protein per minute) and are means ± SD (n = 4). * P < 0.05. C: Effects of calorie restriction on IRAK-1 degradation and JNK phosphorylation. Hepatocytes from aged (20 months) calorie-restricted (CR) or ad libitum-fed (AL) rats were treated with the indicated concentrations of IL-1β for 30 min. IRAK-1 and phospho-JNK levels were determined by Western blotting. β-Actin was used as a control for uniform loading.