PDC study of ordering effects due to nitrous oxide in a model membrane

The gamma-gamma perturbed angular correlation technique has been used to measure the relative motion of lipid molecules in synthetic phospholipid bilayers perfused with the anesthetic gas nitrous oxide. Time-integrated anisotropies for ¹¹¹In, attached to the lipid headgroups, were determined above and below the order-fluid transition temperature. Compared to results with the pure bilayer, the data showed a three-fold decrease above and a four-fold decrease below the phase transition, suggesting a more ordered state of the membrane in the presence of the anesthetic.