β-Hydroxybutyrate Kit (Enzymatic Colorimetric Method)
In vitro test for the quantitative determination of β-HB concentration in human serum or plasma on photometric systems. β-hydroxybutyrate (β-HB) is one of three sources of ketone bodies. Its relative proportion in the blood (78%) is greater than the other two ketone bodies, acetoacetate (20%) and acetone (2%). During carbohydrate deprivation (starvation, digestive disturbances, frequent vomiting), decreased carbohydrate utilization (diabetes mellitus), glycogen storage diseases, and alkalosis, acetoacetate production increases. The increase may exceed the metabolic capacity of the peripheral tissues. As acetoacetate accumulates in the blood, a small amount is converted to acetone by spontaneous decarboxylation. The remaining and greater portion of acetoacetate is converted to β-HB. In diabetics, β-HB measurements can be used for the assessment of the severity of diabetic coma and is essential for the exclusion of hyperosmolar non-ketotic diabetic coma. The measurement of β-HB is also used to monitor insulin requirements, based on existing hyperketonemia.
β-Hydroxybutyrate gets converted to acetoacetate and NADH in the presence of NAD by β-Hydroxybutyrate dehydrogenase. The NADH produced is converted to color using INT and diaphorase. The concentration is determined by measurement of the absorbance change at 505 nm due to INT.