Effect of a long-duration physical exercise on fat cell lipolytic responsiveness to adrenergic agents and insulin in obese men
Abstract
The aim of the study was to investigate whether a long-lasting bout of exercise modifies the lipolytic beta- and anti lipolytiC-alpha(2)-adrenergic effect and the antilipolytic effect of insulin in obese subjects. Biopsies of abdominal subcutaneous adipose tissue were performed before and immediately after 2 h exercise (at 50% of VO2max) on an ergometric bicycle.
Nine healthy obese male subjects (mean age 38.0 +/- 3.5y; mean body mass index (BMI) 35.6 +/- 3.9kg/m(2)) were included in the experiment. The lipolytic responsiveness to adrenaline, isoprenaline (beta-adrenergic agonist), UK-14304 (alpha(2)-adrenergic agonist) and insulin was studied in the isolated fat cell obtained by biopsies of subcutaneous adipose tissue from the peri-umbilical region before and after exercise.
After exercise, an increase was observed in spontaneous lipolytic rate, and in the lipolytic effect of isoprenaline, but no modification in the lipolytic action of adrenaline. Antilipolytic effects of UK-14304 and insulin were not changed by the single bout of exercise.
A single bout of long-term exercise increased the responsiveness of adipose tissue to a-adrenergic stimulation of lipolysis in obese subjects.