[Effect of contrast media on the structure and function of hepatocyte plasma membranes]

The cholecystographic radiopaque agents, adipiodon and endographin, unlike the urographic contrast agents, triombrin and iodamide, decrease the fluorescence intensity of hydrophobic probes 1-anilinonaphthalene-8-sulfonate and 4-dimethylaminochalcone in plasmic membranes (PM) of rat hepatocytes primarily at the expense of the lowering of the constant of probe association with the membranes. The similar but less marked effects were discovered in experiments with lecithin lyposomal preparations. As regards the intensity of action, cardiotrast and triotrast an intermediate position between the two groups of radiographic contrast agents. Adipiodon and endographin induce an inhibition of membranous Mg+2 (Na+, K+) ATPase, which correlates with their effect on the structure of the hepatocyte PM. The data obtained allow a conclusion that, unlike the urographic agents, the cholecystographic radiopaque agents are bound to the definite areas of the hepatocytic PM and provoke alterations in the activity of membranous APTase because of the conformational rearrangements of the membranes.