Cells in human adipose tissue developing into adipocytes.

Sedimentable cells from human adipose tissue of different origins were cultured under conditions when cell multiplication was prevented but lipid filling optimized (suspension culture). In this way an estimation was obtained of the number of in vivo determined adipose precursor cells (preadipocytes) which were not filled with lipid. Under these conditions no cells from adult, non-obese subjects developed to adipocytes. Cells developing to adipocytes constituted less than 0.02% and 1% of adipocytes in tissues from obese adults and from children, respectively. It was concluded that in vivo determined adipocyte precursor cells (preadipocytes, lipid-free fat cells) are not present in a significant number in human adipose tissue either from adults or from children as tested with the method employed, allowing detection of a large number of such cells in adipose tissue from small rats.