Detection of the rat adipose cell glucose transporter with antibody against the human red cell glucose transporter

[¹²⁵1]-protein A and an affinity purified rabbit antibody against the purified human erythrocyte glucose transporter have been used to label rat adipose cell plasma and low-density microsomal membrane proteins after transfer from SDS-polyacrylamide gels to nitrocellulose paper. A major labeled band is observed in both membrane preparations with an apparent molecular weight (approximately 45,000) similar to that of the human erythrocyte glucose transporter. When membranes are prepared from cells incubated in the absence of insulin, the intensity of this band is roughly 2-fold greater in the microsomal membranes than in the plasma membranes. Incubation of cells with a maximally stimulating concentration of insulin, however, increases the intensity of this band in the plasma membranes and concomitantly decreases that in the microsomal membranes. In both cases, the intensity of this band roughly parallels the concentration of glucose transport systems determined by specific D-glucose-inhibitable [³H] cytochalasin B binding. These results indicate that the rat adipose cell glucose transporter is immunologically similar to the human erythrocyte glucose transporter.