The action of phenylarsine oxide on the stereospecific uptake of D-glucose in basal and insulin-stimulated rat adipocytes.

Phenylarsine oxide (PAO) has been used to inhibit the stereospecific uptake of D-glucose in basal and insulin-stimulated rat adipocytes. The inhibition is dose dependent and is partially reversed by dithiothreitol. The results are consistent with a direct interaction between the glucose transporter and PAO. By manipulating the sequence of exposure of cells to PAO and insulin it is possible to differentiate between the effects of PAO on transport into cells with receptor-rich and transporter-rich plasma membranes. PAO rapidly inhibits transport in insulin-stimulated adipocytes but at low concentrations inhibition is transient and recovery of stereospecific uptake takes place after approx. 20 min. The results can be interpreted in terms of the recruitment mechanism of insulin stimulation of transport and demonstrate that a relatively large intracellular pool of transporters exists after insulin stimulation. It also follows that sulphydryl groups probably play a critical role in the mechanism of glucose uptake.