Succinate metabolism uncouples retinal pigment epithelium mitochondria

Succinate is central in energy metabolism. It is thought to be made and consumed within mitochondria, and not to cross the plasma membrane. Contrary to the canonical role of succinate, it is produced in the retina and released into the extracellular milleau. It is unknown how this affects adjacent retinal pigment epithelium, within eyecup tissue. By measuring consumption of 13C4-succinate and O2 we probe metabolism of the eyecup, we find robust succinate consumption by eyecup but not retina tissue. Succinate-dependant stimulation of eyecup respiration is oligomycin resistant; indicating that in eyecup tissue succinate uncouples mitochondrial ATP synthesis from respiration.