Hydroxybutyraat

Hydroxybutyraat is the Dutch term for hydroxybutyrate, the ionized form of hydroxybutyric acid. Several hydroxybutyrate isomers exist, the most biologically important being beta-hydroxybutyrate (3-hydroxybutyrate) and, less prominently discussed in metabolism, gamma-hydroxybutyrate (4-hydroxybutyrate). In biological fluids these compounds are typically present as salts or as the deprotonated anion.

In human metabolism, beta-hydroxybutyrate is a key ketone body produced in the liver during fasting or caloric restriction when carbohydrate availability is limited. It originates from acetyl-CoA derived from fatty acid oxidation and is released into the bloodstream. Tissues such as the heart and brain take up beta-hydroxybutyrate, convert it back to acetyl-CoA, and use it as an energy source through the citric acid cycle.

Beyond its role as an energy substrate, beta-hydroxybutyrate also functions as a signaling molecule. It can influence gene expression and metabolic pathways by engaging receptors and modifying cellular processes, contributing to the regulation of lipolysis and inflammation in some contexts.

Clinically, elevated levels of beta-hydroxybutyrate are characteristic of ketosis and ketoacidosis and can aid in diagnosis and monitoring of metabolic states. Exogenous ketone supplements containing beta-hydroxybutyrate are studied for potential therapeutic and performance-related benefits, though their effects depend on overall metabolic context.

Note that gamma-hydroxybutyrate is a separate compound with distinct pharmacological properties and regulatory considerations; it is not the same as beta-hydroxybutyrate, though both are forms of hydroxybutyrate.