Effect of Membrane Polyunsaturation on Carrier-Mediated Transport in Cultured Retinoblastoma Cells: Alterations in Taurine Uptake

摘要: Neural cell membranes naturally contain a large amount of polyunsaturated fatty acid, but the functional significance this is unknown. An increase in membrane polyunsaturation has been shown previously to affect high-affinity transport systems for choline and glycine cultured human Y79 retinoblastoma cells. To test generality effects on transport, we investigated uptake other putative neurotransmitters amino acids by these Taurine, glutamate, leucine were taken up both high- low-affinity systems, whereas serine, gamma-aminobutyrate, alpha-aminoisobutyrate only systems. The taurine glutamate serine Na+ dependent. Arachidonic acid (20:4) supplementation cells produced enrichment all major microsomal phosphoglycerides with 20:4, while docosahexaenoic (22:6) increases 22:6 content fractions except inositol phosphoglycerides. Enrichment facilitated lowering K'm its system. By contrast, oleic did not uptake. Glutamate, leucine, affected when enriched any acids. These findings demonstrate that certain are sensitive membrane. various either respond differently changes lipid unsaturation, or they located domains modified different extents unsaturation.