Understanding glucose uptake during methionine deprivation in incubated rainbow trout (Oncorhynchus mykiss) hepatocytes using a non-radioactive method.

The role of methionine supplementation in fish metabolism remains largely unexplored. This study investigates the effects of methionine deprivation (MD) on glucose uptake in rainbow trout (Oncorhynchus mykiss) hepatocytes. To this end, primary hepatocytes were incubated in the presence (+M) or the absence (-M) of methionine for 48h and glucose uptake was assessed using a novel non-radioactive, fluorescent-linked enzymatic assay. Evidence indicated that glucose uptake increased under methionine deprivation, primarily due to the increased abundance of membrane bound sodium-glucose transporter 2 (SGLT2), which was likely facilitated by the cellular reduction in [ATP] resulting from increased mitochondrial uncoupling, as supported by elevated transcript levels of uncoupling protein 2a (UCP2a). This study is the first to suggest that the mechanisms responsible for the rapid glucose uptake associated with MR are facilitated by the greater abundance of SGLT2 glucose transporter and mitochondrial uncoupling.