No difference in lipolytic response to ß-adrenoceptor stimulation in situ, but delayed increase in adipose tissue blood flow in moderately obese as compared to lean men in the post-exercise period

This study was undertaken to determine the effect of previous exercise on adipose tissue responsiveness to ß-adrenoceptor stimulation, and on adipose tissue blood flow (ATBF). Eight lean and 8 obese men (BMI: 23.6 ± 2.1 v 29.0 ± 1.9 kg · m-2) were investigated with abdominal subcutaneous microdialysis and 133Xe clearance. A stepwise isoprenaline infusion (10-8, 10-7 and 10-6 mol · L-1) was given in situ in the microdialysis catheter before and 2 hours after a submaximal exercise bout (90 min cycling, 55% of maximal O2 uptake). No differences in response (increase in intercellular glycerol concentration from preinfusion level) to isoprenaline infusions were found between the groups. In both groups, there was no difference in response to post- v preexercise infusion. When the vasodilating agent hydralazine (0.125 g · L-1) was infused into the microdialysis catheter to control for vascular effects of isoprenaline, an interaction effect between exercise and isoprenaline dose was found. Analyses showed an attenuated response to the high isoprenaline dose after exercise (lean: 251 ± 42 µmol · L-1; obese: 288 ± 77 µmol ·