Histidine
HISTIDINE is considered an essential amino acid for children, but not for adults. However, thoughts on that are changing. Technically, it is classified as semi-essential. Although histidine can be produced in small amounts within the adult body, dietary sources are still acknowledged as being the most dependable source of supply.
The neurotransmitter "histamine," which is released during an immune response, is derived from histidine; but, in order for this change to occur, niacin and B6 are required. When the acid group is removed from histidine, it becomes histamine; and both will bind (chelate) with such trace elements as zinc and copper. Histidine is used as a chelating agent in some cases of arthritis; tissue overload of copper, iron, or other heavy metal; and in the treatment of allergies since it goes on to become histamine. Histidine also acts to lower blood pressure and relax blood vessels, and is used to treat various cardiac and circulatory problems.
Large doses of zinc may cause a reduction in the serum histidine levels; whereas, low dosages or prolonged use of zinc has been seen to raise serum histidine and blood histamine. Zinc and manganese deficiencies interfere with the normal metabolism of histidine to histamine. A Vitamin E deficiency also depletes histidine from muscle tissue.
Histidine is known to be vital in the maintenance of the myelin sheaths surrounding nerves, particularly the auditory nerve and is used to treat some forms of hearing disability. Consequently, where there is a deficiency of histidine, nerve deafness is likely.
Histidine plays a significant role in the growth and repair of tissues, ulcers, hyperacidity, digestion, and gastric juices, as well as in the production of red and white blood cells. It is used in the treatment of allergies, rheumatoid arthritis, and anemia. A deficiency is usually found in those with arthritis, chronic renal failure, and who have diminished sexual arousal.
High levels of histidine, leucine and serine can produce psychotic episodes. However, methionine detoxifies histamine and is recommended for some schizophrenics and for those who have high levels of histamine in the bloodstream (histadelic). Methionine is used along with calcium lactate, zinc, and manganese in the treatment.
The Brain Bio Center has shown that histapenic patients have extrememly low levels of histamine in the brain and blood and are usually over-stimulated. However, histadelic patients have high levels of histamine in the brain and blood and are usually suicidally depressed. Thorsons Guide questions the wisdom of giving histidine to histadelic patients displaying symptoms of manic depression unless it can be established that their histamine levels are within normal range.
Soviet scientists have tested over 25,000 different chemical substances and found that histidine and tryptophan are the only elements that provide significant protection against the effects of radiation.
Other names for it include: HIS, amino acid H, and 2-amino-3(imidazole)-propanoic acid.
