抄録
The acute effects of submaximal ergometry exercise on HDL metabolism were studied in 10 healthy males. The bicycle ergometry exercise was performed with 50W of incremental loading every 3 minutes until an end point of 90% of the target heart rate was reached. Changes in the components and particle size of the HDL subpopulations were studied during the exercise protocol. Blood samples were obtained before breakfast after 14 hours of fasting (8:00a.m.), before exercise (10:30a.m.), immediately after submaximal exercise (11:00a.m.), and both one and two hours after exercise. After one week, blood samples were collected from the same subjects over the same time intervals without exercise. HDL2 was separated from HDL3 by ultracentrifugation. The total cholesterol (TC), free cholesterol (FC), triglyceride (TG), and phospholipid (PL) in the HDL subfractions were measured by applying enzymatic methods. The protein content was estimated with bichinchoninic acid. The total lipoprotein mass was determined by adding the TC, TG, PL and protein contents. The particle size of the HDL subfractions was measured by gradient gel electrophoresis.
Two hours after the exercise, TC, esterified cholesterol, PL and the total mass in HDL2 and HDL3 were significantly decreased, while the particle size of both HDL2 and HDL3 were apparently increased relative to thier values before the exercise (both p<0.05). A new HDL subpopulation corresponding to HDL1 immediately appeared after exercise, and disappeared 2 hours after the exercise.
The results obtained in this study indicate that submaximal exercise promoted HDL metabolism, and consequently enhanced cholesterol reverse transport.
