Effect of phenylarsine oxide on protein synthesis in 3T3-L1 adipocytes

In this report, we show that insulin stimulated the incorporation of tracer [3H]leucine into protein of 3T3-L1 adipocytes within 2 min of insulin addition. The concentration of insulin required to elicit 50% activation was 4nM. Phenylarsine oxide, an inhibitor of insulin-stimulated glucose transport, blocked not only insulin-stimulated protein synthesis but constitutive protein synthesis as well (Ki, 3 microM). Importantly, protein synthesis was not required for insulin-activated glucose transport since cycloheximide added either before or after insulin had no effect on the stimulated rates of glucose transport.