Reduced G Protein-coupled Signaling Efficiency in Retinal Rod Outer Segments in Response to n-3 Fatty Acid Deficiency

摘要: The fatty acid (FA) docosahexaenoic (DHA, 22: 6n-3) is highly enriched in membrane phospholipids of the central nervous system and retina. Loss DHA because n-3 FA deficiency leads to suboptimal function learning, memory, olfactory-based discrimination, spatial visual acuity. G protein-coupled receptor (GPCR) signal transduction a common signaling motif these neuronal pathways. Here we investigated effect on GPCR retinal rod outer segment (ROS) membranes isolated from rats raised n-3-adequate or -deficient diets. ROS second generation FA-deficient had approximately 80% less than rats. was replaced by docosapentaenoic (22:5n-6), an n-6 FA. This replacement correlated with desensitization ROS, as evidenced reduced rhodopsin activation, rhodopsin-transducin (G(t)) coupling, cGMP phosphodiesterase activity, slower formation metarhodopsin II (MII) MII-G(t) complex relative FA-adequate ROS. exhibited higher degree phospholipid acyl chain order These findings reported here provide explanation for amplitude delayed response electroretinogram a-wave observed rodents nonhuman primates. Because members family are widespread pathways system, due loss may serve neural deficiency.