RUDN University veterinarians developed a way to protect carp from the harmful effects of ammonia

October 15, 2019

Veterinarians from RUDN University have developed a way to increase the resistance of carp, the most common fish in fish farms, to the harmful effects of ammonia, which is found in almost all water bodies. The researchers found that the amino acid arginine can be helpful if added to fish food. The article was published in the journal Aquaculture.

One of the main problems of fish farms is the pollution of water with ammonia (NH3). The compound gets into water bodies because of human activities: from wastewater treatment plants, with drains from livestock farms and fields where nitrogen fertilisers are used. Ammonia reduces the ability of haemoglobin to bind oxygen, acts on the nervous system, affects red blood cells, and can lead to fish death.

Director of the Department of Veterinary Medicine of RUDN University Yuri Vatnikov and his colleagues have developed a way to use food additives to increase the resistance to ammonia in common carp, a species that is of great economic importance: fish farms sell about four million tons of carp per year, according to the UN Food Organisation (FAO).

The veterinarians conducted two experiments in which they examined the effect of arginine, an amino acid that stimulates the release of growth hormone.

In the first experiment, 600 carp were distributed over 4 tanks and kept there for 10 days, so that the fish adapts to new conditions. After that, for two weeks the fish in each tank was fed following one of four feeding options: with the addition of arginine in the proportion of 0.25%, 0.5%, or 1% by weight of the food, and without the addition of arginine (control group). Then the fish from each tank was distributed over 15 30-liter aquariums, 10 animals each. Then an ammonia solution was being added to the water for 3 hours, concentrations of 0.7, 0.8, 0.9, 1.1, and 1.3 mg / l. And finally, the water was vented and the condition of the fish assessed.

In the second experiment, 60 carp were distributed over 6 aquariums. After two weeks of acclimatisation, for the next 14 days half of the specimens were fed with food to which no arginine was added, and another half was on a diet that included 0.5% arginine. Then, ammonia solution concentration of 0.7 mg / l was added to all tanks. After three hours of exposure to ammonia, the researchers took the blood of carp for analysis.

In the first experiment, the fish exposed to an aqueous solution concentration of 0.7 mg / l ammonia survived regardless of the type of diet. An increase in the dose of ammonia led to the death of some specimens, and with the maximum ammonia concentration of 1.3 mg / l, all fish died. In the group where arginine supplementation was 0.25%, mortality was 5-10% lower. With an increase in the dose of arginine to 0.5%, mortality decreased even more significantly, by about 35%.

The purpose of the second experiment was to study fish blood samples. Exposure to ammonia reduces the content of amino acids, which play an important role in the formation of urea, in particular, the amino acids ornithine and citrulline. The addition of arginine increased the production of amino acids, which enhanced the processing of ammonia into urea. Thus, excess ammonia was excreted from the body.

The problem of the toxic effects of ammonia is of great importance in aquaculture. Fish farmers are interested in ways to suppress the side effects of ammonia. The new study offers a working method based on dietary manipulations: addition of just 0.5% arginine to the carp' food reduces the fish mortality from exposure to ammonia by 35%. The additive activates detoxification, i.e. turning ammonia into urea, and suppresses oxidative stress caused by exposure to ammonia.

RUDN University

Related Amino Acids Articles from Brightsurf:

Igniting the synthetic transport of amino acids in living cells
Researchers from ICIQ's Ballester group and IRBBarcelona's Palacín group have published a paper in Chem showing how a synthetic carrier calix[4]pyrrole cavitand can transport amino acids across liposome and cell membranes bringing future therapies a step closer.

Microwaves are useful to combine amino acids with hetero-steroids
Aza-steroids are important class of compounds because of their numerous biological activities.

New study finds two amino acids are the Marie Kondo of molecular liquid phase separation
a team of biologists at the Advanced Science Research Center at The Graduate Center, CUNY (CUNY ASRC) have identified unique roles for the amino acids arginine and lysine in contributing to molecule liquid phase properties and their regulation.

Prediction of protein disorder from amino acid sequence
Structural disorder is vital for proteins' function in diverse biological processes.

A natural amino acid could be a novel treatment for polyglutamine diseases
Researchers from Osaka University, National Center of Neurology and Psychiatry, and Niigata University identified the amino acid arginine as a potential disease-modifying drug for polyglutamine diseases, including familial spinocerebellar ataxia and Huntington disease.

Alzheimer's: Can an amino acid help to restore memories?
Scientists at the Laboratoire des Maladies Neurodégénératives (CNRS/CEA/Université Paris-Saclay) and the Neurocentre Magendie (INSERM/Université de Bordeaux) have just shown that a metabolic pathway plays a determining role in Alzheimer's disease's memory problems.

New study indicates amino acid may be useful in treating ALS
A naturally occurring amino acid is gaining attention as a possible treatment for ALS following a new study published in the Journal of Neuropathology & Experimental Neurology.

Breaking up amino acids with radiation
A new experimental and theoretical study published in EPJ D has shown how the ions formed when electrons collide with one amino acid, glutamine, differ according to the energy of the colliding electrons.

To make amino acids, just add electricity
By finding the right combination of abundantly available starting materials and catalyst, Kyushu University researchers were able to synthesize amino acids with high efficiency through a reaction driven by electricity.

Nanopores can identify the amino acids in proteins, the first step to sequencing
While DNA sequencing is a useful tool for determining what's going on in a cell or a person's body, it only tells part of the story.

Read More: Amino Acids News and Amino Acids Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to