Glutamate dehydrogenase (GLDH)

Glutamate dehydrogenase (GLDH) assay reagent, Calibrator, Controls and Linearity Checkset

Reagents for the determination of Glutamate dehydrogenase in blood serum

A measurement of Glutamate dehydrogenase or GLDH activity has historically been used as a tool to assess liver damage primarily in larger mammals. More recently GLDH measurements have also been utilized in laboratory animal research. A 2002 study by O’Brien et al (Lab Anim 2002 Jul;36(3):313) noted its value as a preferred biomarker to alanine amino transferase (ALT) in studying liver injury in rats undergoing drug therapy. Rats treated with high levels of Acetaminophen that subsequently developed hepatocellular injury showed no increase is plasma ALT while they demonstrated a marked increase in GLDH. Schomaker et al (Toxocol Sci.2013,132:276) likewise noted the potential value in GLDH measurements in patients with Drug-Induced Liver injury (DILI).

In larger animals GLDH is often used as a complementary assay to Sorbitol dehydrogenase (SDH) in assessing liver damage. Although not normally considered as liver specific as SDH (other than in horses)  GLDH has much greater stability than SDH in the collected sample. It also rises faster after injury and remains elevated longer in the blood system.

Catachem’s GLDH assay is based on the enzyme catalyzing the oxidation of α-ketoglutarate to glutamate with the mediation of NADH as a hydrogen donor and ADP as GLDH activator. The reaction is reversible, although strongly favors the conversion of α-ketoglutarate to glutamate.

Catachem has developed the chemistry into a single stable liquid reagent using a new method of substrate generation. The rate of decrease in optical density (OD) at 340 nm allows the direct measurement of the GLDH enzyme activity. The chemistry demonstrates linearity to 200 U/Liter at 37°C and is easily adapted to run on most chemistry analyzers.

Glutamate dehydrogenase (GLDH) assay reagent – C550-0A – 6 x 25 mL

Glutamate dehydrogenase (GLDH) Calibrator – C550-45– 6 x 1 mL (lyophilized)

Glutamate dehydrogenase (GLDH) Control 1 – C550-46 – 6 x 1 mL (lyophilized)

Glutamate dehydrogenase (GLDH) Control 2 – C550-47 – 6 x 1 mL (Lyophilized)

Glutamate dehydrogenase (GLDH) Linearity Checkset – C550-0L – 5 x 1 mL (Lyophilized)