MULTIPARAMETER FLOW CYTOMETRIC ANALYSIS OF THE EFFECTS OF INDOMETHACIN ON ADIPOCYTE DIFFERENTIATION IN A31T6 CELLS

A31T6 proadipocytes, derived from BALB/c-3T3 clone A31, develop respon siveness to differentiation-promoting agents at density-arrest and dif ferentiate into adipocytes, as determined by the accumulation of cytop lasmic lipid droplets. A flow cytometric assay is being employed to mo nitor the acquisition of aspects of the differentiated phenotype. In t his study, the assay is used to monitor both the rate of differentiati on, as defined by the appearance of cells containing lipid droplets an d the rate of adipocyte maturation, which involves measurement of incr eases in cytoplasmic lipid in cells already committed to the different iation programme. Specifically, we show that 1 treatment with a combin ation of indomethacin and dexamethasone causes the maximum percentage differentiation in the population, 2 addition of indomethacin in combi nation with either dexamethasone or insulin increases the rate of diff erentiation, and 3 indomethacin selectively increases the maturation o f adipocytes, measured as an increase in the amount of lipid per cell. The cytometric assay used in these experiments has allowed determinat ion of the effects of indomethacin on aspects of the adipocyte phenoty pe that cannot be measured by standard techniques.