(Science: biochemistry) Is intricately involved in a large number of critical metabolic processes, ranging from the production of red and white blood cells to regulating antibody activity. Histadine also helps to maintain the myelin sheaths which surround and insulate nerves. In particular, histidine has been found beneficial for the auditory nerves and a deficiency of this vital amino acid has been noted in cases of nerve deafness. Histadine is required for the production of histamine and is often used in the treatment of anaemia, allergies, rheumatoid arthritis and other inflammatory reactions. Histadine also possesses vasodilating and hypotensive actions and has an vital role in sexual responses. Research shows that the release of histamine from the mast cells is necessary for the physical action of orgasm. Women who are unable to achieve orgasm may be low in histamine and can possibly benefit from histidine supplementation. Premature ejaculation is also attributed to excess histamine and may be regulated by using methionine and calcium. Studies show that histidine boosts the activity of suppressor T-cells. One researcher reporting the finding of abnormally low levels of histidine in the blood of patients with rheumatoid arthritis. Histidine is also used as a chelating agent in some cases of arthritis and to treat tissue overload from copper, iron or other heavy metals, to remove them from the body. Histadine also acts as an inhibitory neurotransmitter, boosting the activity of soothing alpha waves in the brain and suporting resistant to the effects of anxiety and stress. In cases of histidine deficiency, there is an unbalancing effect on alpha rhythms, leading to greater beta wave production. Beta waves are responsible for brain activity leading to anger and tension. Histidine is naturally found in most animal and vegetable proteins and is especially high in pork, poultry, cheese and wheat germ. Supplements of histidine should not be larger than 1.5 grams per day, except under a doctors supervision.