The Molecular Mechanism Underlying Continuous Exercise Training-Induced Adaptive Changes of Lipolysis in White Adipose Cells

Figure 1

Lipolysis in white adipocytes is mainly regulated through GPCRs that localize on the plasma membrane. (a) Under stimulatory conditions, ligands binding to GPCRs, that is, -, -, and -AR, activate AC through the action of Gαs, resulting in an increase in PKA activity through the accumulation of intracellular cAMP, and, in turn, PKA phosphorylates and activates HSL. Phosphorylated HSL translocates on the lipid droplet and thereby activates lipolysis. (b) On the other hand, ligands binding to GPCRs, that is, -AR, adenosine-R, and nicotinic acid-R, attenuate lipolysis via a reduction in cAMP production. Insulin receptor signaling also inhibits lipolytic response via the activation of PDH-3B, a cAMP-degrading enzyme.

(a)

(b)