Differentiation of adipocyte precursor cells from obese and nonobese adult women and from different adipose tissue sites.

We studied adipocyte development in primary cultures of stromal-vascular cells from the adipose tissue of obese and nonobese adult women. Adipose conversion was promoted by addition to confluent cultures of 10(-9) mol/l insulin, 10(-7) mol/l cortisol and for the first two days 0.5 mmol/l 1-methyl-3-isobutylxanthine (MIX). Presence of MIX for a longer period resulted in an increasing differentiation rate. No significant difference in the number of developing fat cells was observed between cultures from 8 obese (body mass index 33.6 +/- 4.1 kg/m2) and from 6 lean (body mass index 22.3 +/- 2.4 kg/m2) adults (390 +/- 102 vs. 354 +/- 85 fat cells/cm2, n.s.). The number of new fat cells obtained in cultures from the subcutaneous fat depot was significantly higher as compared to those obtained in cultures from the intraabdominal fat region (360 +/- 68 vs. 79 +/- 35 fat cells/cm2, p less than 0.01), suggesting the existence of regional variations in the differentiation capacity of adipocyte precursor cells.