In vivo lipolysis in adipose tissue from two anatomical locations measuredby microdialysis

In this study, the difference in lipolytic response in inguinal subcutaneou s and epididymal adipose tissues of male Sprague-Dawley rats was assessed i n vivo by microdialysis, Probes were perfused with Ringer solution in which increasing concentrations of isoproterenol (10(-7)-10(-4)mol/L) were added , Glycerol release, expressed as extracellular glycerol concentration, was used as lipolytic index. The effect of isoproterenol on local blood flow wa s investigated using the ethanol technique. No differences were found in th e interstitial glycerol concentration between both adipose tissues under ba sal conditions. When isoproterenol was perfused, a dose-response increase i n glycerol production was induced in both tissues, Interstitial glycerol co ncentration from epididymal adipose tissue was higher than that of inguinal subcutaneous depot at all isoproterenol concentrations. No vasodilatory ef fect of isoproterenol was found. These results suggest that epididymal adip ose tissue is more responsive in vivo to beta-adrenergic lipolysis stimulat ion than is subcutaneous fat pad from the inguinal region. (C) 2000 Elsevie r Science Inc. All rights reserved.