Does diabetes mellitus affect diphenylhexatriene penetration into erythrocyte membrane ghosts?

Diphenylhexatriene transverse distribution has been studied in normal and diabetic erythrocyte membrane ghosts using fluorescence polarization and fluorescence quenching methods. Acrylamide quenched the fluorescence of diphenylhexatriene according to a dynamic mechanism in agreement with Stern-Volmer equation. Nonlinear least-squares analysis based on quenching results has shown greater accessibility of fluorophore to quencher molecules in diabetic ghosts (37.2 +/- 3.2% in normal vs. 67.5 +/- 6.4% in diabetic membranes). Steady-state fluorescence anisotropy measurements evidenced the lowered membrane lipid fluidity in diabetics (anisotropy values: 0.166 +/- 0.011 in normal subjects vs. 0.193 +/- 0.018 in diabetics). A model mechanism is proposed which attributes the lowered capacity of lipid bilayer in diabetes to the increased ordering and more compact structure of membrane phospholipids. The implications of the results for the resolving of steady-state anisotropy data are discussed.