Immune response zinc role

Zinc stimulates the activity of over 100 enzymes for important functions in the body which includes production of insulin and making of sperm and plays a key role in the immune system and DNA synthesis. Zinc helps wounds heal and helps the patient maintain a sense of taste and smeU. A dose of zinc larger than 150 mg can cause copper deficiency, decrease high-density lipoprotein (HDL) cholesterol and weaken the patient s immune response. Zinc also inhibits tetracycline (antibiotic) absorption and therefore should not be taken with antibiotics. The patient should wait two hours after taking any antibiotic before taking zinc. 

Insufficient zinc results in slowed growth, delayed wound healing, poor appetite, mental lethargy, and sexual immaturity and it interferes with the immune response. The main function of zinc in metaboHsm is enzymatic and there is evidence of other physiologic roles, eg, in stabilization of membrane stmcture (57). 

While many a jogger has suggested that exercise can improve his/ her resistance to infectious diseases, conclusive scientific evidence that exercise enhances immune response has yet to be presented. Experimental zinc deficiency in animals may provide a workable model for such investigations. It is well known that exercise induces hypertrophy of adrenal glands with a concomitant increase in the serum concentration of glucocorticoids. Zinc deficiency decreases T cell helper activity and thymic involution followed by a rise in glucocorticoids (98). The observations cited above suggest that it is possible to delineate experimentally the roles of zinc and exercise in immune response. 

A number of agents have been studied for their effects on processes which are thought to be important factors in aging. One hypothesis suggests that an intracellular zinc deficiency may be a primary cause of the aging process (63) since zinc-metaUoenzymes pla.y an important role in many aspects of cellular metabolisiiL A zinc deficiency could result in malproduction of proteins and an accumulation of useless or toxic materials. However, apart from the immune response studies, no therapeutic trials have been conducted to evaluate this hypothesis. 

One of the sites of influence of zinc on immune response may be at the lymphocyte level, since zinc has pharmacological effects on lymphocytes in vitro (Berger and Skinner, 1974). Nude mice, lacking a functional thymus, have an abnormally low plasma level of zinc (Hattler, unpublished results quoted by Schloen et al., 1979). However, the recent demonstration that zinc is essential for the function of serum thymic factor, a polypeptide hormone (Dardenne et al., 1982), supports a direct role for zinc in the maintenance of the immune system. More generally, zinc is an essential coenzyme in many enzyme systems and additional functions of zinc in cell membrane function have been postulated (Bach, 1981). 

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