Influences of tromantadine and nonoxinol 9 on the stability of red cell membrane.

The antiviral compound tromantadine (ViruMerz) and the detergent nonoxinol 9 have been investigated in their effects on biophysical parameters of red cell membranes. Up to a maximum ratio of 1 mol per 800 mol of phospholipids tromantadine enhances the membrane phase transition/separation break at 16-20 degrees C measured by 1-anilinonaphthalene-sulfonate (ANS) fluorescence. It also increases order parameters obtained from spin labeling experiments with 5-doxyl stearic acid.