Single session exercise stimulates formation of preβ1-HDL in leg muscle

Abstract

Physical activity can raise the level of circulating HDL cholesterol. Pre ␤ 1 -HDL is thought to be either the initial acceptor of cellular cholesterol or virtually the first particle in the pathway of the formation of HDL from apolipoprotein A-I and cellular lipids. We have therefore sought to identify pre ␤ 1 -HDL in arterial and venous circulations of exercising legs in healthy individuals and in subjects with stable Type 2 diabetes mellitus. Blood samples were taken simultaneously from the femoral artery and vein before and after 25 min cycling exercise. The major findings were, first, that exercise significantly increased plasma concentration of pre ␤ 1 -HDL (20% increase, P Ͻ 0.05) and second, that the pre ␤ 1 -HDL concentration was significantly higher in the venous compared with the arterial blood both before and after exercise in both diabetics and controls. In the combined population, formation of pre ␤ 1 -HDL at rest was 9.9 ؎ 5.2 mg/min and exercise enhanced pre ␤ 1 -HDL formation 6.6-fold in both groups.

Physical Fitness and Reverse Cholesterol Transport

“…This finding is consistent with previously reported increases in pre␤ 1 -HDL after exercise. 16,17 We have previously demonstrated that pre␤ 1 -HDL is generated during passage of blood from artery to vein across human leg muscles and that this can be substantially stimulated by exercise. 16 Because athletes have a bigger muscle volume, we speculate that muscle may be an important source of higher pre␤ 1 -HDL levels in athletes.…”

Physical activity and its effects on lipids

“…An existing hypothesis is that HDL cholesterol may be synthesized by exercising muscle [30] through the activation of LPL, which stimulates the clearance of TG-rich lipoproteins (eg, very low-density lipoprotein [VLDL], LDL cholesterol, and chylomicrons) in order to supply free fatty acids to exercising muscle [31,32]. As exercised muscle cells become depleted of TG, cellular cholesterol may be mobilized and released to HDL [33]. Kiens and Lithell [30] compared the production of HDL cholesterol in a pretrained leg muscle with an untrained counterpart in six healthy participants.…”

Endurance training enhances ABCA1 expression in rat small intestine

“…HDL3-Cholestrol was determined according to Gidez et al (Sviridov et al 2003). Briefly after precipitation of apoB-containing lipoproteins with heparin-Mn'', HDL3 was precipitated by addition of dextran sulfate (MW 15,000, 0.13 g/dl) (Sviridov et al 2003).…”

“…It was shown that acute exercise, exercise training, and fitness can favorably affect the several key steps in RCT such as Enhanced cellular cholesterol efflux (Brites et al 2004), increased formation and size of Apo A-I (Wilund et al 2002;Olchawa Beata 2004), increased plasma pre-b HDL levels (Jafari et al 2003;Sviridov et al 2003), increased LCAT activity (Cumhur Kilinç et al 2000;Olchawa Beata 2004;Tsopanakis et al 1988), and increased HDL-C level (Durstine et al 2001). But studies to examine the effect of exercise training on ABCA1 are really rare.…”