Effect of acute exercise on mRNA and protein expression of main components of the lipolytic complex in different skeletal muscle types in the rat.

Abstract

Adipose triglyceride lipase (ATGL) hydrolyses the first bond of triacylglycerols. The activity of the enzyme is elevated by comparative gene identification 58 (CGI-58), and reduced by G0/G1 switch gene 2 (G0S2) protein. There are no data on the effect of acute exercise on the behavior of particular components of the lipolytic complex in different skeletal muscle types, therefore, the aim of the present study was to examine that topic. The experiments were carried out on four groups of male Wistar rats: 1) control 2) rats running on a treadmill at the speed of 18 m/min for 30 min, 3) at the speed of 18 m/min for 120 min, 4) for 30 min at the speed of 28 m/min. We found that each exercise bout induced numerous changes in the expression of mRNA and protein ATGL, hormone-sensitive lipase, CGI-58 and G0S2 in the investigated muscles. These changes, depended to a large extent on a muscle type. In general, the strongest pro-lipolytic response was observed in the soleus, followed by the red section of the gastrocnemius (RG). On the other hand, in the white section of the gastrocnemius protein expression of the components of the lipolytic complex was reduced in response to exercise. These changes were not accompanied by alterations in muscle triacylglycerol content, with the exception of a reduction observed in the RG following 2-hour run. We conclude that a single bout of exercise induces significant effect on the expression of components of the lipolytic complex in skeletal muscle, and that the magnitude of this effect depends on muscle oxidative capacity, as well as the duration and intensity of exercise.