Changes

==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 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.

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.

==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>.

==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 [[Nutrition Glossary#Chelator|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>.

==Consequences of Histidine Deficiency==

==Consequences of Histidine Deficiency==

==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).

==Diagnosing Histidine Deficiency==

==Diagnosing Histidine Deficiency==

==References==

==References==

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[[Category:Amino Acids]]

[[Category:Amino Acids]]