The urine of a healthy person does not contain Bence-Jones protein, which is represented by light chains of immunoglobulins that are detected as a result of the formation of malignant tumor processes.
Homocysteine is a product of amino acid metabolism (the conversion of methionine to cysteine). Approximately 70% of plasma homocysteine is bound to albumin, 30% is oxidized to disulfide, and only 1% is free.
Ammonia is a product of protein metabolism, formed in all tissues. The largest amount of ammonia (80%) is formed inside the intestine under the influence of bacteria.
Uric acid is a product of the metabolism of purine bases, which are part of complex proteins - nucleoproteins. The resulting uric acid is excreted by the kidneys.
The Reberg-Tareev test allows one to judge glomerular filtration and tubular reabsorption in the kidneys. The test is based on the fact that creatinine is filtered only by the glomeruli, is practically not absorbed and is secreted by the tubules in insignificant quantities.
The daily excretion of creatinine in urine is relatively constant, equivalent to the daily formation and directly depends on muscle mass and the excretory capacity of the kidneys.