EFFECT OF MEMBRANE POLYUNSATURATION ON CARRIER-MEDIATED TRANSPORT IN CULTURED RETINOBLASTOMA CELLS - ALTERATIONS IN TAURINE UPTAKE
EFFECT OF MEMBRANE POLYUNSATURATION ON CARRIER-MEDIATED TRANSPORT IN CULTURED RETINOBLASTOMA CELLS - ALTERATIONS IN TAURINE UPTAKE
复制标题
DOI：
10.1111/j.1471-4159.1984.tb09726.x
复制
发表时间：
1984-01-01
影响因子：
4.7
通讯作者：
SPECTOR, AA
中科院分区：
文献类型：
--
作者：
YOREK, MA;STROM, DK;SPECTOR, AA
Neural cell membranes naturally contain a large amount of polyunsaturated fatty acid, but the functional significance of this is unknown. An increase in membrane polyunsaturation affected the high-affinity transport systems for choline and glycine in cultured human Y79 retinoblastoma cells. The uptake of other putative neurotransmitters and amino acids by these cells was used to investigate the effects of membrane polyunsaturation. Taurine, glutamate and leucine were taken up by both high- and low-affinity transport systems, whereas serine, GABA and .alpha.-aminoisobutyrate were taken up only by low-affinity systems. The high-affinity taurine and glutamate and low-affinity serine uptake systems were Na+ dependent. Arachidonic acid (20:4) supplementation of Y79 cells produced enrichment of all the major microsomal phosphoglycerides with 20:4, while docosahexaenoic acid (22:6) supplementation produced large increases in the 22:6 content of all fractions except the inositol phosphoglycerides. Enrichment with these polyunsaturated fatty acids facilitated taurine uptake by lowering the K''m of its high-affinity transport system. Enrichment with oleic acid did not affect taurine uptake. Glutamate, leucine, serine, GABA and .alpha.-aminoisobutyrate uptake were not affected when the cells were enriched with any of these fatty acids. Only certain transport systems are sensitive to the polyunsaturated fatty acid content of the retinoblastoma cell membrane. The various transport systems either respond differently to changes in membrane lipid unsaturation, or they are located in lipid domains that are modified to different extents by changes in unsaturation.
