Neurotransmitter movements in nerve endings. Influence of substances that modify the interfacial potential.
Polysialogangliosides, sulphatides, glycerylmonooleate, unsaturated fatty acids, myelin basic protein and sucrose inhibit the Na+-coupled uptake and induce a Ca2+-dependent release of dopamine from nerve endings. Substances chemically related to those referred to above, such as monosialogangliosides, neutral glycosphingolipids, glycerylmonostearate, saturated fatty acids and albumin, do not show these effects. Mixtures of polysialogangliosides or sulphatides with myelin basic protein or albumin inhibit, to different degrees, the effects of the individual components. The decreased uptake induced by sucrose reverted to control levels upon reduction of the concentration of the perturbing agent. The restoration of the uptake was probably mediated by the Na+-pump reconstituting the transmembrane Na+-gradient necessary for the Na+-coupled cotransport of dopamine. It is suggested that the effects of uptake inhibitor or release inducer agents derive from their ability to decrease the surface potential and modify the molecular organization of phospholipid interfaces which can result in changes of the membrane ionic permeability.
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D005260:Female; D005732:Gangliosides / Q000494:pharmacology; D006834:Hydrazines / Q000494:pharmacology; D007700:Kinetics; D008055:Lipids / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D051381:Rats
D005732:Gangliosides; D006834:Hydrazines; D008055:Lipids; D004298:Dopamine