lattato

Lactate (lattato in Italian) refers to the conjugate base of lactic acid or to salts such as sodium lactate and calcium lactate. Lactic acid is 2-hydroxypropanoic acid; in aqueous solution, lactate predominates at physiological pH.

Lactate exists as two enantiomers: L-lactate and D-lactate. In humans, the L form is produced during glycolysis from pyruvate by lactate dehydrogenase, regenerating NAD+. D-lactate is produced by some bacteria and, in rare conditions, may accumulate in humans if gut flora produce excess and absorption occurs.

Physiological role: Lactate is not only a waste product; it can be transported between tissues by monocarboxylate transporters (MCTs). The "lactate shuttle" links glycolytic tissues (muscle) with oxidative tissues (heart, brain) and the liver. In the liver, lactate can be converted back to glucose via gluconeogenesis (Cori cycle).

Clinical relevance: Blood lactate concentration is used as a marker of tissue hypoxia and metabolic stress. Normal adult blood lactate is about 0.5–2.2 mmol/L; levels above 4 mmol/L suggest lactic acidosis. Lactic acidosis is classified as Type A (hypoxia or shock) or Type B (metabolic or drug-related).

Applications: Lactate salts are used in medicine, for example lactated Ringer's solution as an intravenous fluid. In food and cosmetic industries, lactates act as buffering agents and preservatives. In fermentation, bacteria produce lactate during lactic acid fermentation.