[Study of the process of ACTH and insulin interaction with the plasmatic membranes of rat liver cells in vitro using luminescence methods].

The process of interaction of ACTH and insulin with plasmatic cellular membranes of the rat's liver and artificial lipid membranes (liposomes) was studied by the method of proper proteinic fluorescence and by using hydrophobic fluorescent probes. This process is shown to be attended by conformative readjustments of the membranous proteins and also by definite structural changes in the lipid phase of the membranes. In its action ACTH involves the hydrophobic layer of the lipid phase to a greater extent than does insulin. A comparison of the data on the effect produced by ACTH and insulin on the plasmatic membranes as against the results obtained with liposomes suggests that for the hormones to display their activity these have first to combine with the specific membranous protein, while a change in the lipid phase comes only as a consequence of such an interaction.