What is arginine
Arginine or l-arginine is an essential dibasic amino acid required by cats and dogs for optimum growth and development. It features an alpha amino and carboxylic acid groups as an aliphatic side chain.
Its amino group (nitrogen-containing group) has a positive charge and it is its binding site to other molecules.
Its intestinal absorption occurs in the ileum (jejunum) with the aid of dibasic amino acid transporters while it is actively reabsorbed in the kidney at the proximal tubule.
Cats are very sensitive to this amino acid. A deficiency results in not only hyperammonemia (acute ammonia intoxication) but also death within a few hours since unlike other animals cats cannot synthesize it from glutamine due to the low activity of the involved enzymes,
Human beings can produce it in their intestine from ornithine and citrulline, but a feline’s level of the required enzyme for this production is low.
Some of the foods high in arginine include nuts and seeds (peanuts, walnuts, sesame, hazelnuts, pumpkin seeds), turkey, pork loin, chicken, beef, soybeans, chicken peas, seaweed (spirulina), dairy, lentils, corn, cereals, oats, buckwheat among others.
- Its primary function is being part of a countless synthesis of proteins required for optimum growth and development.
- It’s a precursor of biogenic amines necessary for replication of cells.
- It helps in ammonia detoxification, i.e., it is a key urea intermediate whose absorption from diets, “acts both anaplerotically to stimulate urea synthesis and as an allosteric activator of acetylglutamate, which in turn, is an essential allosteric activator of carbamoyl-phosphate synthase, the first enzyme in the detoxification of ammonia and the synthesis of urea,” notes NRC.
- It evokes the release of several metabolic meditators as well as hormones including insulin, gastrin, and glucagon.
- Therapeutically, it can reduce urinary orotic acid.
- It is a nitric oxide precursor. Nitric oxide (NO) has several roles as a neurotransmitter – it helps in blood vessels relaxation and hence affects blood pressure and assists macrophages in killing germs or foreign bodies.
The requirement in these pets is higher to help handle the higher need for detoxifying ammonia formed during protein degradation.
According to AAFCO 2014, the minimum amounts of arginine required by felines on a dry matter basis is 1.24% for reproducing or growing cats while the value will be 1.04% for adult maintenance. These amounts will be 3.10g and 2.60 g per 1000 kcal of cat food based on metabolizable energy.
Arginine deficiency in cats
Deficiencies are diagnosed by fasted plasma amino acid levels or a check for urinary orotic acid.
Giving cats diets deficient of arginine with considerable amounts of other amino acids results in some symptoms of severe hyperammonemia noted after 1-3 hours and death may result due to ammonia intoxification.
That is, “cats may suffer from a toxic buildup of ammonia in the bloodstream”, states National Research Council (NRC). This is because arginine is involved in the elimination of ammonia via their urine as already noted.
Some of the symptoms of hyperammonemia included emesis, vocalization, ataxia, hyperactivity, hyperesthesia, apnea, tetanic spasms, excessive salivation (ptyalism), depression, cyanosis, and their limbs become stretch with their claws visible.
However, including citrulline or ornithine prevents hyperammonemia while normal growth occurred in cases where only ornithine was added to diets lacking arginine.
Arginine synthesis in a cat’s kidney to satisfy needs for growth and produce enough for urea synthesis is possible if citrulline is exogenously provided to these pets.
Finally, milder symptoms such as diarrhea, excessive weight loss, urinary orotic aciduria, refusal to eat (inappetence) and learned taste aversion are noted in case of free-feeding with diets that do not have arginine.
There is no need for supplementation as most of the foods that form part of your feline’s friend diet have this essential amino acid.
However, if you need them, there are some supplements which contain it. Some, such as Life Extension Cat Mix (Advanced Multi Nutrient Formula) Grams Powder contain taurine, vitamin B, essential fatty acids, probiotics, among other ingredients.
Kittens have shown a decreased growth rate in case of diets that have are 5-10 times more arginine than the required amounts without any serious immediate effects
In adult cats, there are no reports or significant effects on an excessive amount of this amino acid.