The effects of calcium channel blocking drugs on the thermotropic behavior of dimyristoylphosphatidylcholine

Analysis of the tangled relationships between P‐glycoprotein‐mediated multidrug resistance and the lipid phase of the cell membrane

“…Numerous studies have investigated in detail their partition and location within lipid bilayers (e.g. [27,38–44]). One salient feature stemming from these studies is the great number of parameters that affect this interaction, including the nature of the lipids (headgroup as well as fatty acid structure); physical state of the bilayer (which in turn depends on many factors); and composition of the aqueous buffer (Fig.…”

Ethylazinphos Interaction with Membrane Lipid Organization Induces Increase of Proton Permeability and Impairment of Mitochondrial Bioenergetic Functions

“…A large number of drugs with different chemical structures and pharmacological effects are able to accumulate in membrane lipid domains, changing their organization and physical properties and, consequently, their function (Sikkema et al, 1995;Mouritsen and Jørgensen, 1998), since the preservation of an exact degree of organization is essential for most membrane activities (Eze, 1990;Mouritsen and Jørgensen, 1998;Williams, 1998). Examples of the above compounds include anesthetics, calcium channel blocking drugs, alcohols, and insecticides (Makriyannis et al, 1986;Bae et al, 1989;Barry and Gawrisch, 1994;Mavromoustakos et al, 1995;Antunes-Madeira et al, 1996). In particular, the influence of organochlorine and organophosphorus insecticides on the physical properties of lipid bilayers and implications at the level of membrane cell function have been studied in our laboratory (Antunes-Madeira and Madeira, 1993; AntunesMadeira et al, 1994 AntunesMadeira et al, , 1996Videira et al, 1996Videira et al, , 1999aLopes et al, 1997;Donato et al, 1997).…”

Calcium (45Ca) uptake inhibition by calcium (Ca2+)‐channel blockers in the presence of two atpase inactivators

“…Ion channels are proteinaceous openings that span the plasma membrane and conduct ions on a concentration gradient that, primarily, influence ion influx (2). Ion channels, also, have specific receptor sites to which ion channel blockers attach (2,3,4). Nifedipine attaches to a receptor site at, or close to, the plasma membrane surface (3,4).…”

“…Ion channels, also, have specific receptor sites to which ion channel blockers attach (2,3,4). Nifedipine attaches to a receptor site at, or close to, the plasma membrane surface (3,4). Diltiazem and verapamil attach at separate sites that are in the lipid soluble portion of the plasma membrane and close enough together that steric hindrance may occur (3,4).…”

“…Nifedipine attaches to a receptor site at, or close to, the plasma membrane surface (3,4). Diltiazem and verapamil attach at separate sites that are in the lipid soluble portion of the plasma membrane and close enough together that steric hindrance may occur (3,4). Ion carriers are ATPases that span the plasma membrane and have multiple sulfhydiyl groups at least one of which is plasma (2).…”