Indicator indicators that may characterize the state of the final stages of amino acid metabolism and the adequacy of the liver to the kidneys to ensure these processes is the residual nitrogen levels. Most informativeness have not integrated in this indicator, that is – azotemia – too much content of all nitrogen-containing blood components, and changes in the content of each component of residual nitrogen. Impairment of the function of hepatocytes affects the activity of the processes of deamination and transamination of amino acids. This is reflected in the increase of amine component of the residual nitrogen. Parallel can be observed violation mochevinoobrazovatelnoy liver function. In these cases, the increase in nitrogen content of amino acids, glutamine and ammonium salts in the blood is accompanied by a decrease in the concentration of urea. Perhaps the development of isolated violations mochevinoobrazovatelnoy function in hereditary deficiency of enzymes ornitinovogo cycle.
The most frequent consequence of violation of urea synthesis is the accumulation of blood ammonia, has a pronounced cytotoxic effect, especially for cells of the nervous system. In the body evolved a number of compensatory processes that ensure the binding of ammonia. That 80% of ammonia coming from the intestine through the aortic vein into the liver, is converted into urea, a quarter of the resulting urea is secreted into the intestine, with the remainder excreted by the kidneys. Ammonia is not transmitted through ornitinovy cycle, the presence of glutamine synthetase and atp converted into glutamic acid, and then – in glutamine. Glutamine is transported by blood to the liver and kidneys, where glutaminase hydrolyzes to free ammonia that is converted then into urea or communicate with hydrogen ions and released in the form of ammonium salts in the urine. The latter process, called ammoniogenezom, is an important mechanism for the maintenance of acid-base balance. This provides a cycle of glutamine, which is a form of transport and provision of ammonia.
