[Insulin-induced structural transformations in the plasma membranes of liver and fat cells]

Two classes of SH-groups have been revealed with Ellman's reagent in isolated plasma membranes of epididimal fat cells from rats. Preincubation with 2 x 10(-9) M insulin (25 degrees C, 30 min) results in a 15% decrease of content of the fast reacting groups. The effect was absent in preparations solubilized with 0,06% Triton X-100 or 0,1% SDS. In the presence of insulin the rates of solubilization of liver plasma membranes by these two detergents have been found to increase. It is suggested that binding of insulin to receptor initiates the generalized structural rearrangement in both types of membranes.