Adipose tissue metabolism and cell size: variation between subcutaneous sites and the effect of copper supplementation

Abstract
Adipose tissue cell volume, lipolytic rates, Iipoprotein lipase (LPL) and acetyl CoA carboxylase (ACC) activities were determined in biopsy samples taken from the back, shoulder, rump and groin subcutaneous fat depots of 17-month-old female sheep (no. = 24). Half of the sheep had received a copper (Cu) supplement at 6 weeks of age. Biopsy samples were taken after fasting overnight.Differences in cell volume and ACC activity were apparent between sites. Supplementation with Cu at 6 weeks of age led to a proportional increase of between 0·24 and 0·45 in adipose cell volume and a proportional increase in lipolysis which varied from 0·70 to 2·27 depending on site and hormone addition. Correlations between sites for cell volume and lipolytic activity were not high in general but those for ACC and LPL activities were higher (for ACC r = 0·40 to 0·79). Overall the best correlations were between the back and rump sites. Correlations between the various metabolic measurements and cell volume were not apparent within treatment groups.