Energy Substrate Requirements of Rat Retinal Pigmented Epithelial Cells in Culture: Relative Importance of Glucose, Amino Acids, and Monocarboxylates

Abstract

Rat RPE cells require glucose as their primary metabolic substrate in culture, but can metabolize glutamine in its absence. When glucose and glutamine are limiting, RPE cells can metabolize monocarboxylates such as lactate or pyruvate. These data provide evidence that such cells are able to withstand various types of insult brought about by nutrient deprivation, by altering their pathways of energy production.

Glucose Metabolism in Mouse Cumulus Cells Prevents Oocyte Aging by Maintaining Both Energy Supply and the Intracellular Redox Potential1

“…when monocarboxylate transfer into the oocyte or mitochondria was inhibited with 4-CIN, oocyte activation increased to the highest level in the presence of either pyruvate, lactate, or glucose. This suggested that as in other cell types [67,68], transportation of lactate and pyruvate across the plasma membrane and into mitochondria was also dependent on the MCTs in the aging oocyte. Furthermore, the present study showed that unlike lactate, pyruvate did not rely solely on electron transport for its inhibition of oocyte aging.…”

The Mitochondrial Complex I Inhibitor Rotenone Induces Endoplasmic Reticulum Stress and Activation of GSK-3β in Cultured Rat Retinal Cells

“…Rat retinal cell cultures comprising both neurons and glia were prepared using a trypsin-mechanical digest procedure previously described. 17,18 Briefly, retinas were enucleated from 1-to 2-day-old rat pups and incubated in physiological buffer (solution medium; 120 mM NaCl, 5.4 mM KCl, 24 mM NaHCO 3 , 0.1 mM NaH 2 PO 4 , 3 g/L BSA, 20 mM glucose, and 0.15 mM MgSO 4 , 28 lM phenol red) containing 0.1 mg/mL trypsin (Sigma-Aldrich) at 378C for 8 minutes. After the reaction was stopped, cells were resuspended in minimal essential medium (MEM) containing 10% FBS, 10 mg/mL gentamicin sulfate, 200 lM glutamine, and 25 mM glucose and applied to 13-mm-diameter borosilicate glass coverslips (immunocytochemistry), 6-well plates (Western blot), or 12-well plates (ATP assay and reactive oxygen species determination), all of which had previously been coated with 10 lg/mL poly-D-lysine, for 2 hours.…”

A hypothesis to suggest that light is a risk factor in glaucoma and the mitochondrial optic neuropathies

“…MTT is reduced to an insoluble, blue formazan product because of acceptance of electrons from cellular reducing equivalents such as NADH, NADPH, or succinate, thus providing an assay for the REDOX state of a sample. 36 The REDOX potential is a measure of the oxidative status of a cell-a fall in the potential implies that the balance is in favour of oxidation, as might arise through the action of ROI. WST-1 (4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate) is a tetrazolium dye containing an electron coupling agent that is cleaved by mitochondrial dehydrogenases to a formazan dye with an absorbance at 490 nm (Roche, USA).…”