ACCELERA TED COMMUNICATION Adipocyte Fatty Acid-Binding Protein: Regulation of Gene Expression In Vivo and In Vitro by an Insulin-Sensitizing Agent

Pioglitazone, a thiazolidinedione, is a novel antidiabetic corn-pound that can lower blood glucose in diabetic rodents by increasing insulin sensitivity in target tissues. We have previously demonstrated that pioglitazone can enhance the insulin- or in-sulin-like growth factor-i-regulated differentiation of 3T3-Li cells, a cell line that undergoes morphological and biochemical differentiation to mature adipocytes [Mo!. Pharmaco!. 41:393-398 (1992)]. In this study, we have examined the effect of pioglitazone on the expression ofthe adipocyte fatty acid-binding protein (aFABP) in ob/ob mice and 3T3-Li cells. Administration of the drug to mice was observed to cause a dose-dependent increase in aFABP mRNA expression in epididymal fat, which was correlated with a decrease in blood glucose and insulin levels. Treatment of 3T3-Li cells with pioglitazone enhanced aFABP expression in a time-dependent fashion. To explore