Increase in membrane fluidity in liposomes and plant protoplasts upon osmotic swelling.

Osmotic gradient across the membrane of nonsonicated liposomes and rose petal protoplasts are shown to induce swelling. Concomitantly, the lipid fluidity as measured by fluorescence depolarization is increased, probably due to increase in molar free volume. It is suggested that osmotic swelling can affect cell physiology via changes in membrane fluidity.