Morphologic studies of human subcutaneous adipose tissue in vitro

A simple method for in vitro studies of human subcutaneous adipose tissue is described. Explants of adipose tissue have been maintained in vitro for 30 weeks in Parker medium 199. The morphology of cultured explants compared well with that of freshly excised specimens. In the absence of serum there was no outgrowth of fibroblast‐like cells. When human serum was added to the medium at concentrations exceeding 5% there was a proliferation of fibroblast‐like cells. This cell proliferation could still be obtained when serum was added after two weeks of culture in a serum free medium. The adipose cells were isolated with collagenase and the cell size determined. Explants with an initial mean cell size larger than about 95 μ showed a significant decrease in cell size during the incubation. This could not be attributed to a traumatic effect. Metabolic differences between large and small adipose cells was suggested as a possible reason.