4-Methyl-2-oxovaleric acid (Ketoleucine, 4-MOV, KIC, 4-Methyl-2-oxopentanoic acid, alpha-Ketoisocaproic acid, alpha-ketoisocaproate, 2-Oxoisohexanoate) is released by Astrocytes to neurons and can be reaminated by aminotransferase to leucine. 4-Methyl-2-oxovaleric acid reduces the rate of protein degradation in skeletal muscle. 4-Methyl-2-oxovaleric acid acts as an uncoupler of oxidative phosphorylation (OXPHOS) and as a metabolic inhibitor possibly through its inhibitory effect on alpha-ketoglutarate dehydrogenase (oxoglutarate dehydrogenase complex, OGDC) activity.