Liquimax Urea Birthlot (Modified Berthelot Method)

The determination of urea is the most widely used test for the evaluation of kidney function. The test is frequently used in conjunction with the determination of creatinine for the differential diagnosis of prerenal hyperuremia (cardiac decompensation, water depletion increased protein catabolism), renal hyperuremia (glomerulonephritis, chronic nephritis. polycystic kidney, nephrosclerosis, tubular necrosis) and postrenal hyperuremia (obstructions of the urinary tract). Urea is the final degradation product of protein and amino acid metabolism. In protein catabolism the proteins are broken down to amino acids and deaminated. The ammonia formed in this process is metabolized to urea in the liver. This is the most important catabolic pathway for eliminating excess nitrogen in the human body. In 1914 Marshall introduced an assay based on the enzyme urease for determining urea in blood. The ammonia released from urea by urease was measured titrimetrically. Numerous other techniques have since been employed to measure the ammonia produced. These include Berthelot’s indophenol assay and the reaction of ammonia with Nessler’s reagent.