Biologists from Russian town of Puschino developed a new technique for fighting hyperammonemia. This disease starts, when patient’s blood contains too much free ammonium ions that may lead to encephalopathy and death. Russian scientists have something to suggest in order to help those suffering from serious illnesses, caused by disturbances of urea cycle in an organism.

Ammonia is essential for normal functioning of any cell; however, high concentrations of this chemical agent are extremely toxic. Human organism is known to produce about 20 grams of ammonia every day. Concentration of this nitrogen and hydrogen compound is regulated by enzymes of urea cycle, located in liver. Excessive ammonia or dysfunction of enzyme system leads to hyperammonemia – pathologically high concentration of ammonia in blood. This situation is very dangerous, since ammonia causes functional disturbances of central nervous system, and plays significant role in development of such diseases as cirrhosis, liver encephalopathy, alcohol intoxication and Alzheimer’s disease. Newborn children with hyperammonemia use to die within two days.

Modern medicine already developed some means for fighting this problem, however, their efficiency leaves much to be desired. Hemodialysis and some drugs may drop ammonia concentration in blood, but the result shows up in several days. Until nowadays, both Russian and world medical and biological science never developed fast-response techniques of lowering ammonia concentration in blood. Russian biologists succeeded.

 

 

Hyperammonemia is often caused by insufficiency of glutamine-synthetase, one of ammonia-utilizing enzymes. Russian scientists suggest using this enzyme as therapy and delivering it to an organism by means of erythrocytes – red blood cells. This combination was called “ammocyte” – erythrocyte with “preinstalled” enzyme system, aimed at lowering ammonia concentration in blood. Ammocytes deliver enzymes in blood, where they neutralize excessive ammonia.

Researchers isolated red blood cells from rodent blood and “filled” them with glutamine-synthetase under low osmotic pressure. After that cells with enzymes were injected into mice, which suffered from moderate hyperammonemia after being injected with ammonium acetate. Then researchers measured ammonia concentration in blood in time intervals of 30, 60 and 120 minutes. Results of the experiment showed that ammonia concentration in blood dropped two-fold in 30 minutes, and four-fold – in 120 minutes. Control group of mice did not receive any ammocytes and displayed stable high content of ammonia in blood.

Therefore, biologists from Puschino created a new and effective biotechnology, which is very promising, like any therapy. The patent for the development is pending since 2007. Researchers believe that ammocytes will find effective application in medical and veterinary practice and wait for funding to introduce their development to real life.

Source: Science & Technologies

Kizilova Anna