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| ==What is Histidine?== | | ==What is Histidine?== |
− | Histidine is an '''essential amino acid''' for dogs and cats. It is characterised as a gluconeogenic amino acid and contains a positively charged imidazole side chain. Dietary histidine is absorbed by a neutral amino acid transporter in the small intestine (particularly the jejunum) and plasma histidine is actively reabsorbed in the proximal tubule of the kidney. | + | Histidine is an [[Amino Acids Overview - Nutrition|'''essential amino acid''']] for dogs and cats. It is characterised as a gluconeogenic amino acid and contains a positively charged imidazole side chain. Dietary histidine is absorbed by a neutral amino acid transporter in the [[Small Intestine Overview - Anatomy & Physiology|small intestine]] (particularly the [[Jejunum - Anatomy & Physiology|jejunum]]) and plasma histidine is actively reabsorbed in the [[Nephron Microscopic Anatomy#Proximal Tubule|proximal tubule]] of the kidney. |
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| ==Why is it Important?== | | ==Why is it Important?== |
− | Histidine is a '''structural component of proteins; it plays a key role in oxygen exchange''', and is a precursor of biologically active compounds such as histamine and carnosine<ref>National Research Council (NRC). Protein and Amino Acids. In Nutrient Requirements for Dogs and Cats. 2006 Washington, DC: National Academies Press p. 122-123.</ref>. | + | Histidine is a '''structural component of [[Protein Overview - Nutrition|proteins]]; it plays a key role in oxygen exchange''', and is a precursor of biologically active compounds such as histamine and carnosine<ref>National Research Council (NRC). Protein and Amino Acids. In Nutrient Requirements for Dogs and Cats. 2006 Washington, DC: National Academies Press p. 122-123.</ref>. |
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| ==Roles in the Body== | | ==Roles in the Body== |
− | Histidine is present at high concentrations in haemoglobin; the positive charge on the imidazole side chain of this amino acid promotes oxygen exchange in the lungs and other tissues<ref>Cianciaruso B, et al. Histidine, an essential amino acid for adult dogs. J Nutr 1981;111:1074-1084.</ref>. | + | Histidine is present at high concentrations in [[Erythrocytes#Function|haemoglobin]]; the positive charge on the imidazole side chain of this amino acid promotes oxygen exchange in the lungs and other tissues<ref>Cianciaruso B, et al. Histidine, an essential amino acid for adult dogs. J Nutr 1981;111:1074-1084.</ref>. |
− | Histamine a neuro-active compound is formed from the decarboxylation of histidine, and plays a role in immune function and vasodilation. Carnosine is a histidine derived dipeptide that acts as a cellular antioxidant and copper and zinc chelator within mammalian cells<ref>Boldyrev AA, et al. Physiology and pathophysiology of carnosine. Physiol Rev 2013;93:1803-1845.</ref>. | + | '''Histamine a neuro-active compound is formed from the decarboxylation of histidine, and plays a role in immune function and vasodilation'''. '''Carnosine is a histidine derived dipeptide that acts as a cellular antioxidant and [[Copper - Nutrition|copper]] and [[Zinc - Nutrition|zinc]] [[Nutrition Glossary#Chelator|chelator]] within mammalian cells'''<ref>Boldyrev AA, et al. Physiology and pathophysiology of carnosine. Physiol Rev 2013;93:1803-1845.</ref>. |
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| ==Consequences of Histidine Deficiency== | | ==Consequences of Histidine Deficiency== |
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| ==Dietary Sources== | | ==Dietary Sources== |
− | Sufficient histidine is found in plant and animal protein sources, such as muscle meat, eggs, dairy protein (i.e., casein), cereal grains, and pulses (i.e.,legumes). | + | Sufficient histidine is found in plant and animal protein sources, such as muscle meat, eggs, dairy protein (i.e. casein), cereal grains, and pulses (i.e. legumes). |
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| ==Diagnosing Histidine Deficiency== | | ==Diagnosing Histidine Deficiency== |
− | Diagnosis of histidine deficiency is based on fasted plasma amino acids and the presence of hypoalbuminemia and low serum haemoglobin concentration. | + | Diagnosis of histidine deficiency is based on fasted plasma amino acids and the presence of [[Hypoalbuminaemia|hypoalbuminemia]] and low serum haemoglobin concentration. |
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| ==References== | | ==References== |
| <references/> | | <references/> |
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− | [[Category:To Do - Nutrition]] | + | <br> |
| + | {{Reviewed Nutrition 1 |
| + | |date = 19 May 2015}} |
| + | {{Waltham}} |
| + | {{OpenPages}} |
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| + | [[Category:Amino Acids]] |