Information On Histidine

Histidine is an essential amino acid during infancy, and its synthetic pathways in older children and adults are poorly understood. According to "Nelson's Textbook of Pediatrics" the clinical signs of a lack of the enzyme which acts in the metabolism of histadine can include impaired speech, growth retardation or mental retardation. However, whether these findings are actually related to lack of histidine is unclear since children who are defficient in histidine can be completely normal.

The importance of the amino acid histidine lies in the fact that the body uses it to manufacture histamine, and histamine is responsible for a wide range of physiological processes. It is common knowledge that histamines cause the swelling and reddening in many inflammations and allergic reactions. Doctors therefore often prescribe antihistamines in the treatment of inflammations and infections, as well as allergies.

Histidine is a metalloprotein that can bind and transport several metals, including copper and iron. It also increases calcium absorption, reduces histamine levels, and in turn controls diarrhea. (Too much histidine will actually cause constipation, and this is overcome by taking zinc and GLA in the form of primrose, borage, or black current oil.) Since diarrhea causes dehydration and loss of electrolytes, histidine can greatly enhance performance by countering this effect. Histidine is also an important mechanism in clotting factors and can minimize internal bleeding from microtrauma.

As the major component of zinc-binding proteins, histidine is essential for zinc absorption and transport to tissues. One study showed that histidine supplementation stimulated growth by increasing zinc absorption, which in turn thickened the growth plate in bone. Zinc is also a factor in insulin sensitivity, prostaglandin synthesis, and immune function. Another critical role for histidine is myelin basic protein. Because of this protein's zinc-binding properties, myelin is compacted and provides more nerve-insulating protection.

Less known is the important role, histamines play in sexual functions. By and large it is histamines that regulate ejaculations and orgasms. Men suffering from premature ejaculations often show increased histamine activity. They may be helped by an amino acid which counteracts the formation of histamine from histidine, or the activity of histamine, namely methionine.

Contrarily, men and women having difficulties achieving orgasms may be helped by histidine supplementation, as this may result in increased histamine levels in the sexual tract, which in turn may make orgasms and ejaculations easier. Older men who experience a slow down in sexual response may also ask their doctors about histidine supplementation.

An additional pro-sexual effect of histidine may lay in its vasodilating effect, thus making blood flow to the sex organs easier.

Apart from its sexual functions, histidine is involved in many other physiological processes. It is necessary for the production of red and white blood cells and supports the activity of suppressor T cells.

Histidine is used as a supplement for sufferers of rheumatoid arthritis, since it has been shown that in these patients, histidine levels are low. And last not least, histidine is, like many other amino acids, important for growth and general tissue repair.

In the heart, the ability of histidine to act as an electron donor and, thereby, to neutralize singlet oxygen and the hydroxyl radical results in improved contractility and heart function during heart attack and cardiac procedures such as angioplasty, heart bypass, heart transplant. Cellular (tissue) damage occurs in a wide variety of medical conditions, including infectious diarrheal diseases, ophthalmic surgery, ideopathic bowel diseases, cardiac conditions, transplant surgery, the central nervous system, and the administration of radiation therapy and chemotherapeutic agents.

Histidine has been administered to both animals and humans in dozens of studies for numerous conditions. The metabolic pathway, pharmacokinetics, and safety of histidine are all well known. Preclinical studies by CYTOS have demonstrated that histidine is very effective in preventing cellular (tissue) damage in a wide variety of ischemic and inflammatory conditions.

Histidine protects cells by the following:

  • Scavenging reactive oxygen species called singlet oxygen and the hydroxyl radical;
  • Inhibiting lipid peroxidation;
  • Preserving glutathione levels;
  • Protecting the nitric oxide (NO) cycle; and
  • Reacting with and inactivating inflammatory mediators such as cytokines and prostaglandins.

Histidine is able to protect cells (i.e., tissue) during inflammation by using one or more of these biochemical processes simultaneously.

  • Van Wouwe, J.P.; Veldhuizen, M.; Growth characteristics in laboratory animals fed zinc-deficient, copper-deficient, of histidine-supplemented diets. Biol. Trace Elem. Res., 55(1-2):71-7, Oct-Nov, 1996
  • Horrobin, D.F.; Mandu, M.S.; Oka, M.; Morgan, R.O.; Cunnane, S.C.; Aly, A.I.; Ghayur, T., Schweitzer, M.; and Karmali, R.A.; The nutritional regulation of T lymphocyte function. Med. Hypothesis, 5(9):969-85, Sep., 1979
  • Tsang, D.; Tsang, Y.S.; Ho, W.K.; and Wong, R.N.; Myelin basic protein is a zinc-binding protein in brain: possible role in myelin compaction. Neurochem. Res., 22(7):811-9, July, 1997
  • Dr. Hess, Dr. Kukreja. Cytoprotection by Histidine via Reactive Oxygen Scavenging. Cytos Pharmaceuticals LLC

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