Lack of antilipolytic effect of lactate in subcutaneous abdominal adipose tissue during exercise

The purpose of our study was to evaluate the potential inhibition of adipos e tissue mobilization by lactate. Eight male subjects (age, 26.25 +/- 1.75 yr) in good physical condition (maximal oxygen uptake, 59.87 +/- 2.77 ml.kg (-1).min(-1); %body fat, 10.15 +/- 0.89%) participated in this study. For e ach subject, two microdialysis probes were inserted into abdominal subcutan eous tissue. Lactate (16 mM) was perfused via one of the probes while physi ological saline only was perfused via the other, both at a flow rate of 2.5 mu l/min. In both probes, ethanol was also perfused for adipose tissue blo od flow estimation. Dialysates were collected every 10 min during rest (30 min), exercise at 50% maximal oxygen consumption (120 min), and recovery (3 0 min) for the measurement of glycerol concentration. During exercise, glyc erol increased significantly in both probes. However, no differences in gly cerol level and ethanol extraction were observed between the lactate and co ntrol probes. These findings suggest that lactate does not impair subcutane ous abdominal adipose tissue mobilization during exercise.