Native zinc deficiency and immunoreactivity

摘要

Zinc is an essential trace element played an important role in the facility of many biological reactions. More than two hundred zinc metalloenzymes have been identified in the plant and animal kingdoms (Hallolloran, 1993; Valle and Falchuk, 1993). It is known that among all essential nutrients zinc plays an important role in the immune functions. It has been shown that zinc deficiency causes limphopenia, thymic atrophy and T cell immunity function depression (Fraker et al., 1987; Prasad, 1998). There are scientific data that have been suggested zinc involvement in the regulation of apoptosis. Zinc deficiency may induce glucocorticoid-mediated apoptosis (Fraker et al., 2000). The zinc content decrease in the organism ( < 13,1 μmol/l in blood serum) causes the zinc deficiency state (ZDS) (Karlinsky, 1983). Zinc deficiency is widespread throughout the developing countries of mid-East and is characterized by the syndrome of "adolescent nutritional dwarfism" as well as psychoneurological, epidermal, gastrointestinal, skeletal, reproductive, immune lesions (Prasad et al., 1961). Subclinical deficiencies in zinc are prevalenced in industrialized countries of the world. Manifestations of marginal zinc status may be limited only by immune effects (Fraker et al., 1993). The cause of mild zinc deficiency is revealed to be associated with the decreased bioavailable zinc content in diet. The normal diet zinc content comes to 15 g/l (Committee on Dietary Allowances, Food and Nutrition Board, National Research Council, 1980). In the United States, suboptimal intake of dietary zinc has been observed in children from low income families, low birth weight infants, frail elderly persons, children with chronic diarrhea and some pregnant teenagers (Endre et al., 1990; Sazawal et al., 1998). The lack of animal protein and prevalence of phitates in food are considered the causes of nutritional zinc deficiency (Prasad et al., 1961). However, little is known about the impact of biogeochemical conditions of the environment on human zinc status. On the territory of Chuvashia there is the Prikubnino-cyvilski subregion of biosphere that is characterized by the decrease of the zinc level in the soil ( < 0,1 g/kg) and consequently in the food biogeochemical chain of inhabitants. In this region the zinc content in human diet achieves only 9,1g/d. (Suslikov and Semenov, 1981). The Chuvash Republic is located on the west bank of the Volga River in the central part of European Russia.