Zinc deficiency reproduction

In addition to their endocrine disrupting properties, it must be appreciated that many of the chemicals in question possess more general toxic properties, which may be potentiated by metabolism by the organism. Several PAHs, PCBs and PCDDs are carcinogenic, while certain phthalate esters can enhance the excretion of zinc, potentially leading to zinc deficiency. Zinc, an essential element, plays a vital role in spermatogenesis and mature T-cell production. Deficiency may result in abnormalities of the male reproductive system, depletion of spermatogenesis and suppression of the immune system. 

Zinc deficiency places an increased demand on selenium (Se) pools in daphnids. As little as 5 pg Se/L in zinc-free water eliminated overt cuticle damage and substantially increased reproduction, but did not alter the shortened life span. Cladocerans at the threshold of Se deficiency will become overtly Se deficient when zinc supplies are lacking (Keating and Caffrey 1989). Insufficient copper introduces cuticle problems in daphnids similar to those introduced by insufficient zinc or... 

The balance between excess and insufficient zinc is important. Zinc deficiency occurs in many species of plants and animals, with severe adverse effects on all stages of growth, development, reproduction, and survival. In humans, zinc deficiency is associated with delayed sexual maturation in adolescent males poor growth in children impaired growth of hair, skin, and bones disrupted Vitamin A metabolism and abnormal taste acuity, hormone metabolism, and immune function. Severe zinc deficiency effects in mammals are usually prevented by diets containing >30 mg Zn/kg DW ration. Zinc deficiency effects are reported in aquatic organisms at nominal concentrations between 0.65 and 6.5 pg Zn/L of medium, and in piscine diets at <15 mg Zn/kg FW ration. Avian diets should contain >25 mg Zn/kg DW ration for prevention of zinc deficiency effects, and <178 mg Zn/kg DW for prevention of marginal sublethal effects. 

Although a-D-mannosidase appears to be under endocrine control,28,28 its natural function remains obscure. It is probable that the enzyme is important in the catabolism of D-mannose-containing glycoproteins,12,16,88 and, therefore, that the important trace element zinc could be indirectly implicated in this process. It is well known that zinc deficiency has an adverse effect on fertility in the male,89,90 and it could be argued that the changes observed in a-D-mannosidase activity in uterus and epididymis indicate that this enzyme is important in reproduction. It is scarcely justifiable to ascribe a cause-and-effect relationship to the correlations observed between the zinc content and the a-D-mannosidase activity in epididymis. All that can be said with any certainty is that, under certain circumstances, the two variables respond together to a common stimulus. 

Zinc Essential to all organisms used jo >70 enzymes aa-bilizes coiled ribosomes. Flays a role in sexual maturation and reproduction. U.S. population marginally deficient. Moderately to slightly toxic orally causes vomiting and diarrhea/ Pollution from industrial smoke may cause lung disease use of zinc promotes cadmium pollution. Certain areas (e.g., Iran and Egypt) are zinc deficient."... 

Zinc-deficient rats develop fissures at the comers of the mouth, a poor hair coat, scaly feet, and a kangaroo-like posture. Reproductive defects are common. The female rats fail to have an estrus cycle, and the males show atrophy of the testicles and do not produce sperm. 

Swenerton, H-, and Hurley, L, S, (1980), Zinc deficiency in rhesus and bonnet monkeys, including effects on reproduction. /. Wutr. 110,575-. 3. 

Zinc is an essential micronutrient for plants, humans, and animals. Zinc deficiency has relatively litde effect on the health of a plant, but it interferes with reproduction. Pea plants deprived of zinc, for example, will form flowers. But the flowers will not turn to seeds. 

In humans, zinc deficiencies are more serious. Zinc is used to build molecules of DNA. DNA is the chemical in the body that tells cells what chemicals they should make. It directs the reproduction of humans also. 

Zinc deficiency includes depressed feed intake, stunted growth, skin lesions, and reproductive difficulties. Zinc is a component of enzymes which catalyze more than fifty different biochemical reactions, as well as a component of proteins involved in gene expression. The recommendation for zinc intake amounts to 30 mg kg for calves, heifers and lambs, 40 mg kg for dairy cows, piglets, pigs, sows and hens, and 50 mg kg feed DM for broilers. 

Zinc deficiency occurs in populations whose diets contain high concentration of phytate, a powerful chelator, and low protein (Tapiero and Tew, 2003). Zinc deficiency negatively affects the epidermal, central nervous, immune, gastrointestinal, skeletal, and reproductive systems (Salgueiro et al, 2000,2002 Tapiero and Tew, 2003 Verstraeten ef aZ., 2004). 

Reproductive Effects. Daily oral exposure to zinc sulfide to women during the last two trimesters did not cause any complications in pregnancies (Mahomed et al. 1989). No studies were located regarding reproductive toxicity in humans after inhalation or dermal exposure to high levels of zinc. Zinc deficiency in humans has been shown to result in abnormalities of labor, atonic bleeding, pre-term labor, and post-term pregnancies. 

Bedwal RS, Nair N, Mathur RS. 1991. Effects of zinc-deficiency and toxicity on reproductive-organs, pregnancy and lactation - a review. Trace Elements in Medicine 8(2) 89-100. 

With regard to phthalates, DEHP has been shown to irrduce rrraterrral liver MT arrd lead to a functiorral zinc deficiency in the embryo indicating that altered Zn metabolism may contribute to DEHP-irrduced reproductive toxicity and teratogerricity. Irrtubation of... 

Deficiencies of protein, vitamins and minerais affect reproduction indirectiy, through their effects on the generai heaith of animais, but a few have more specific effects on reproduction. Thus, zinc deficiency in maies reduces the production of spermatozoa, and vitamin A deficiency causes congenitai abnormaiities in foetuses. 

Zinc plays a fundamental role in human fertility and reproduction. A crude but indicative piece of evidence in this regard is that semen contains a large amount of zinc and zinc deficiencies are associated with low sperm counts. More formally, the production and development of sperm depends on a zinc-activated protein, human protamine 2 (HP2). Displacing zinc, lead binds itself to HP2 and in the process alters the structure of the protein. Zinc-related processes are also linked to the transcription and translation of human DNA. The genetic code would remain inert if not for its coupling to RNA, which carries the code, as it... 

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