Effects of short-term fasting and pharmacological activation of AMPK on metabolism of rat adipocytes.

AMP-activated protein kinase (AMPK) is a key intracellular energy sensor and regulates processes associated with energy metabolism. In the present study, effects of AICAR, a pharmacological activator of AMPK, on metabolism of adipocytes of non-fasted and 12-h fasted rats were compared. It was shown that in fat cells of control rats, epinephrine- and dibutyryl-cAMP-induced lipolysis was markedly reduced in the presence of AICAR. However, in adipocytes of fasted animals, the lipolytic response was not significantly affected by AICAR. Moreover, in cells of control rats, the inhibitory effect of insulin on epinephrine-induced lipolysis was markedly deepened in the presence of AICAR. However, this effect was not shown in fat cells of fasted rats. This indicates that pharmacological activation of AMPK by AICAR influences metabolism of adipocytes of non-fasted rats, however, AICAR fails to affect metabolism of these cells under conditions of fasting.