Editing Lactic acid (section)

=== Brain development metabolism ===
Some evidence suggests that lactate is important at early stages of development for brain metabolism in [[prenatal]] and early [[postnatal]] subjects, with lactate at these stages having higher concentrations in body liquids, and being utilized by the brain preferentially over glucose.<ref name=zilberter2010/> It was also hypothesized that lactate may exert a strong action over [[GABA]]ergic networks in the [[brain development|developing brain]], making them more [[inhibitory]] than it was previously assumed,<ref>{{cite journal | vauthors = Holmgren CD, Mukhtarov M, Malkov AE, Popova IY, Bregestovski P, Zilberter Y | title = Energy substrate availability as a determinant of neuronal resting potential, GABA signaling and spontaneous network activity in the neonatal cortex in vitro | journal = Journal of Neurochemistry | volume = 112 | issue = 4 | pages = 900–12 | date = February 2010 | pmid = 19943846 | doi = 10.1111/j.1471-4159.2009.06506.x | s2cid = 205621542 | doi-access = free }}</ref> acting either through better support of metabolites,<ref name=zilberter2010/> or alterations in base intracellular [[pH]] levels,<ref>{{cite journal | vauthors = Tyzio R, Allene C, Nardou R, Picardo MA, Yamamoto S, Sivakumaran S, Caiati MD, Rheims S, Minlebaev M, Milh M, Ferré P, Khazipov R, Romette JL, Lorquin J, Cossart R, Khalilov I, Nehlig A, Cherubini E, Ben-Ari Y | title = Depolarizing actions of GABA in immature neurons depend neither on ketone bodies nor on pyruvate | journal = The Journal of Neuroscience | volume = 31 | issue = 1 | pages = 34–45 | date = January 2011 | pmid = 21209187 | pmc = 6622726 | doi = 10.1523/JNEUROSCI.3314-10.2011 }}</ref><ref>{{cite journal | vauthors = Ruusuvuori E, Kirilkin I, Pandya N, Kaila K | title = Spontaneous network events driven by depolarizing GABA action in neonatal hippocampal slices are not attributable to deficient mitochondrial energy metabolism | journal = The Journal of Neuroscience | volume = 30 | issue = 46 | pages = 15638–42 | date = November 2010 | pmid = 21084619 | pmc = 6633692 | doi = 10.1523/JNEUROSCI.3355-10.2010 }}</ref> or both.<ref>{{cite journal | vauthors = Khakhalin AS | title = Questioning the depolarizing effects of GABA during early brain development | journal = Journal of Neurophysiology | volume = 106 | issue = 3 | pages = 1065–7 | date = September 2011 | pmid = 21593390 | doi = 10.1152/jn.00293.2011 | s2cid = 13966338 }}</ref>

Studies of brain slices of mice show that [[beta-hydroxybutyrate|β-hydroxybutyrate]], lactate, and pyruvate act as oxidative energy substrates, causing an increase in the NAD(P)H oxidation phase, that glucose was insufficient as an energy carrier during intense synaptic activity and, finally, that lactate can be an efficient energy substrate capable of sustaining and enhancing brain aerobic energy metabolism ''in vitro''.<ref>{{cite journal | vauthors = Ivanov A, Mukhtarov M, Bregestovski P, Zilberter Y | title = Lactate Effectively Covers Energy Demands during Neuronal Network Activity in Neonatal Hippocampal Slices | journal = Frontiers in Neuroenergetics | volume = 3 | pages = 2 | year = 2011 | pmid = 21602909 | pmc = 3092068 | doi = 10.3389/fnene.2011.00002 | doi-access = free }}</ref> The study "provides novel data on biphasic NAD(P)H fluorescence transients, an important physiological response to neural activation that has been reproduced in many studies and that is believed to originate predominantly from activity-induced concentration changes to the cellular NADH pools."<ref>{{cite journal | vauthors = Kasischke K | title = Lactate fuels the neonatal brain | journal = Frontiers in Neuroenergetics | volume = 3 | pages = 4 | year = 2011 | pmid = 21687795 | pmc = 3108381 | doi = 10.3389/fnene.2011.00004 | doi-access = free }}</ref>

Lactate can also serve as an important source of energy for other organs, including the heart and liver. During physical activity, up to 60% of the heart muscle's energy turnover rate derives from lactate oxidation.<ref name="Parks"/>