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Created page with "==What is Threonine?== Threonine is an essential amino acid for dogs and cats. Threonine is characterised as a gluconeogenic amino acid and contains a hydroxyl side chain whic..."
==What is Threonine?==
Threonine is an essential amino acid for dogs and cats. Threonine is characterised as a gluconeogenic amino acid and contains a hydroxyl side chain which is chemically reactive. Dietary threonine is absorbed by a neutral amino acid transporter in the small intestine (particularly the jejunum) and plasma threonine is actively reabsorbed in the proximal tubule of the kidney.
==Why is it Important?==
Threonine is a component of structural proteins. The hydroxyl group on the side chain of threonine often serves as the site for phosphorylation and de-phosphorylation reactions that control the activities of many proteins and enzymes<ref>National Research Council (NRC). Protein and Amino Acids. In Nutrient Requirements for Dogs and Cats. 2006 Washington, DC: National Academies Press p. 130-131.</ref>.
==Roles in the body==
The phosphorylation/dephosphorylation of the threonine hydroxyl groups on proteins by either is serine/threonine kinase or serine/threonine phosphatase, respectively, controls activity of normal physiologic function, such as insulin release<ref>Ortsader H, et al. Protein phosphatase in pancreatic islets. J Endo 2014;221:R121-R144.</ref> or cellular apoptosis<ref>Depaoli-Roach AA, et al. Serine/threonine protein phosphatases in the control of cell function. Adv Enz Regul 1994;34:199-224. </ref>.
==Consequences of Threonine Deficiency==
Dogs: Puppies fed a threonine-deficient diet experienced decreased food intake and weight loss<ref>Burns RA and Milner JA. Threonine, tryptophan and histidine requirements of immature beagle dogs. J Nutr 1982;112:447-452.</ref>.
Cats: Feeding of a threonine-deficient diet to kittens caused decreased food intake and weight loss<ref>Rogers QR and Morris JG. Essentiality of amino acids for the growing kitten. J Nutr 1979;109:718-723. </ref>, as well as cerebellar dysfunction resulting in ataxia, tremors, and incoordination that was reversible with threonine supplementation<ref>Titchenal CA, et al. Threonine imbalance, deficiency, and neurological dysfunction in the kitten. J Nutr 1980;110:2444-2459.</ref>.
==Toxicity==
There are no studies on either acute or chronic toxicity related to feeding high doses of threonine to dogs and no reports of safe upper limits. Kittens fed purified diets containing threonine at 9x the requirement for growth showed no adverse effects.7 There are no studies on acute or chronic toxicity of high dose threonine in adult cats.
==Dietary Sources==
Sufficient threonine is found in plant and animal protein sources, such as muscle meat, eggs, dairy protein (e.g., casein), cereal grains, and pulses (i.e., legumes).
==Diagnosing Threonine Deficiency==
Diagnosis of threonine deficiency is based on fasted plasma amino acids.
==References==
<references/>
[[Category:To Do - Nutrition]]
Threonine is an essential amino acid for dogs and cats. Threonine is characterised as a gluconeogenic amino acid and contains a hydroxyl side chain which is chemically reactive. Dietary threonine is absorbed by a neutral amino acid transporter in the small intestine (particularly the jejunum) and plasma threonine is actively reabsorbed in the proximal tubule of the kidney.
==Why is it Important?==
Threonine is a component of structural proteins. The hydroxyl group on the side chain of threonine often serves as the site for phosphorylation and de-phosphorylation reactions that control the activities of many proteins and enzymes<ref>National Research Council (NRC). Protein and Amino Acids. In Nutrient Requirements for Dogs and Cats. 2006 Washington, DC: National Academies Press p. 130-131.</ref>.
==Roles in the body==
The phosphorylation/dephosphorylation of the threonine hydroxyl groups on proteins by either is serine/threonine kinase or serine/threonine phosphatase, respectively, controls activity of normal physiologic function, such as insulin release<ref>Ortsader H, et al. Protein phosphatase in pancreatic islets. J Endo 2014;221:R121-R144.</ref> or cellular apoptosis<ref>Depaoli-Roach AA, et al. Serine/threonine protein phosphatases in the control of cell function. Adv Enz Regul 1994;34:199-224. </ref>.
==Consequences of Threonine Deficiency==
Dogs: Puppies fed a threonine-deficient diet experienced decreased food intake and weight loss<ref>Burns RA and Milner JA. Threonine, tryptophan and histidine requirements of immature beagle dogs. J Nutr 1982;112:447-452.</ref>.
Cats: Feeding of a threonine-deficient diet to kittens caused decreased food intake and weight loss<ref>Rogers QR and Morris JG. Essentiality of amino acids for the growing kitten. J Nutr 1979;109:718-723. </ref>, as well as cerebellar dysfunction resulting in ataxia, tremors, and incoordination that was reversible with threonine supplementation<ref>Titchenal CA, et al. Threonine imbalance, deficiency, and neurological dysfunction in the kitten. J Nutr 1980;110:2444-2459.</ref>.
==Toxicity==
There are no studies on either acute or chronic toxicity related to feeding high doses of threonine to dogs and no reports of safe upper limits. Kittens fed purified diets containing threonine at 9x the requirement for growth showed no adverse effects.7 There are no studies on acute or chronic toxicity of high dose threonine in adult cats.
==Dietary Sources==
Sufficient threonine is found in plant and animal protein sources, such as muscle meat, eggs, dairy protein (e.g., casein), cereal grains, and pulses (i.e., legumes).
==Diagnosing Threonine Deficiency==
Diagnosis of threonine deficiency is based on fasted plasma amino acids.
==References==
<references/>
[[Category:To Do - Nutrition]]