Interactions of malondialdehyde and 4-hydroxynonenal with rat liver plasma membranes and their effect on binding of prostaglandin E(2) by specific receptors

We investigated effect of aldehydic products of Lipid peroxidation, malondialdehyde (MDA) and 4-hydroxynonenal (HNE) on prostaglandin (PG) E(2) receptors of liver plasma membranes. The modification of the membranes by MDA diminished PGE(2) binding, decreasing receptor affinity for PGE(2) and receptor density whereas HNE increased PGE(2) binding, enhanced receptor density but did not changed receptor affinity. ESR study showed the decrease of the whole membrane fluidity after modification by MDA whereas HNE lowered membrane fluidity only in the internal zone of lipid bilayer and increased it in the surface area. The possible effects of membrane changes caused by MDA and HNE on PGE(2) receptor parameters are discussed.