Effect of infrequent feeding and increased physical activity on cholesterol kinetics in the rat

The authors studied the effect of chronic physical exercise (running in a rotating drum at 850 m/hour, 5 times a week for 16 weeks) on the size of the cholesterol body pools and on cholesterol kinetics in adult male Wistar rats fed on a standard diet either ad libitum or 2 hours daily [33 weeks]. These data were obtained by mathematical analysis of the curve expressing the correlation of specific plasma cholesterol activity to time after a single dose of cholesterol-4-14C. Chronic physical stress and infrequent feeding, as separate experimental stimuli, both caused cholesterol to shift from the blood plasma at a higher rate and reduced the size of one or both cholesterol body pools (with quick or slow turnover, pools A and B). Physical exercise also reduced fractional cholesterol turnover in pool A. When the two stimuli were combined, i.e. in infrequently fed and chronically stressed rats, the rate of the cholesterol shift from the blood plasma slowed down, the total and irreversible shift of cholesterol from pool A diminished and the production rate in this pool also fell.