Treadmill exercise enhances ABCA1 expression in rat liver

ATP-binding cassette transporters (ABCs) belong to a large family and include 49 mammalian transmembrane transporters that transfer a variety of substrates across the lipid bilayers in an energy-dependent manner. ABCA1 is a member of this family which plays a crucial role in plasma HDL-C remodeling. The purpose of this study was to investigate liver ABCA1 expression and plasma HDL level in response to treadmill running program in rats. Ten adult Wistar male rats (12–14 weeks old, 200–220 g) were used for this study. Animals were divided into control (Con, n = 5) and Training (TR, n = 5) groups. Training group was given exercise on a motor-driven treadmill at 25 m/min (0% grade) for 90 min/day, 5 days/week for 6 weeks. Rats were sacrificed 24 h after the last session of exercise portion of the liver was excised, immediately washed in ice-cold saline, and frozen in liquid nitrogen for extraction of ABCA1 mRNA. Plasma was collected for HDL-C, LDL, TC, TG, and VLDL-C measurements. Liver ABCA1 mRNA expression was significantly (P < 0.001) higher in trained rats compared to control rats. Plasma HDL-C, LCAT, pre-β-HDL concentrations were significantly higher (P < 0.01, P < 0.001, P < 0.028, respectively) in trained rats at the end of treadmill exercise. However, plasma lipids, other lipoproteins and TC/HDL and LDL/HDL ratio were unchanged. In conclusion, a treadmill running-induced elevated plasma HDL-C concentration was accompanied with a higher liver ABCA1 mRNA expression and increased in LCAT and pre-β-HDL levels.