Cadmium antagonisms

Nation JR, Grover CA, Bratton GR, et al. 1990. Behavioral antagonism between lead and cadmium. Neurotoxicol Teratol 12 99-104. 

Sunda, W. G. and Huntsman, S. A. (1996). Antagonisms between cadmium and zinc toxicity and manganese limitation in a coastal diatom, Limnol. Oceanogr., 41, 373-387. 

Harrison, G. I. and Morel, F. M. M. (1983). Antagonism between cadmium and iron in the marine diatom Thalassiosira weissflogii, J. Phycol, 19, 495-507. 

Cationic antagonisms induced by trace elements excesses have been demonstrated in plants as well as animals. Excesses of either manganese or iron in soil have resulted in deficiencies of the other in soybeans (152). Likewise, excess soil concentration of copper has resulted in manganese deficiency in crops (153). Plants, like animals, also demonstrate chromosomal aberrations (particularly to aluminum and cadmium) (15) as well as enzymatic alterations in response to excess exposure (16). 

Interactions Overabundance of one trace element can interfere with the metabolic use of another element available at normal levels. For example, addition of large amounts of zinc to a diet interferes with (antagonizes) intestinal copper absorption, resulting in copper deficiency from a diet with adequate copper content. Copper deficiency can provoke iron deficiency and anaemia. Molybdenum deficiency in animals can be induced by co-administration of large amounts of the similar element tungsten. Iron deficiency can also increase retention of cadmium and lead, and selenium has been proposed to protect against cadmium and mercury toxicity. 

Antagonism may be defined as the situation in which the toxicity of two or more compounds present or administered together or sequentially is less than would be expected in terms of their toxicities when administered separately. Antagonism may be due to chemical or physical characteristics of the pollutants, or it may be due to the biological actions of the pollutants involved. For example, the highly toxic metal cadmium (Cd) is known to induce anemia and nephrogenic hypertension as well as teratogenesis in animals. Zinc (Zn) and... 

Data concerning the toxicity of the four discussed toxic minerals are presented in Tables 4.5 and 4.6. The uptake of elements is not entirely independent of one another. Elements of similar chemical properties tend to be taken up together. Sometimes one element has an inhibiting effect on another, or there can be a synergistic effect, e.g., enhancement of absorption of calcium in the presence of adequate amounts of phosphorus, or cadmium and lead hindering calcium and iron absorption, or zinc and copper antagonism and their influence on the ratio of Zn/Cu on copper deficiency. 

Cadmium. Selenium can antagonize the nephrotoxic and hepatotoxic effects of cadmium in rats (Flora et al. 1982 Lindh et al. 1996 Nehru and Bansal 1996 Stajn et al. 1997), the inflammation, atrophy, and necrosis induced by cadmium in testes of rats (Jones et al. 1997 Mason and Young 1967 Ohta and Imamiya 1986 Wlodarczyk et al. 1995 Yiin et al. 1999), and the cardiotoxicity of cadmium in rats (Jamall et al. 1989). The protective effects are thought to occur as a result of the formation of a selenium-cadmium complex of high molecular weight (Chen et al. 1975 Jamall et al. 1989 Jamba et al. 1997 Ohta and Imamiya 1986). 

Comparing the results of cadmium concentration in placentas and blood of newborn children from the Kikinda area with those from the Novi Sad area, the reverse relationship is noticed (Figs. 3 and 6). In order to find an explanation for this, and based on knowledge from the literature that there is metabolic antagonism between cadmium and zinc at tissue level, and that zinc has an antitoxic affect in relation to cadmium. 

The poisoning effects of foreign metals are often traceable to cation antagonism. Thus lead, a well-known neurotoxin, displaces calcium from several parts of the nervous system, thus hindering release of neurotransmitters (Kober and Cooper, 1976). The widespread contamination by cadmium on the West Coast of Japan, coupled with a low calcium intake, caused the painful disease itai itai , a form of osteomalacia, around 1960. This turned out to be a straightforward case of cadmium—calcium antagonism (Friberg, 1974). 

Kar, A. B., Das, R. P., and Mukerji, B., 1960, Prevention of cadmium induced changes in the gonads of rats by zinc and selenium—A study in antagonism between metals in the biological system, Proc. Natl. Inst. Sci. India Part B Biol. Sci. 26 40. 

Chronic experiments using combined exposures to multiple carcinogenic metals, such as would occur most frequently in human exposures (Waalkes and Oberdorster 1990), have not been carried out with cadmium. However, cadmium can both enhance and antagonize the carcinogenic effects of several organic carcinogens (Harrison and Heath 1986 Kurokawa et al. 1985 Wade et al. 1987 Waalkes et al. 1991c). The incidence of diethyl-... 

Waalkes MP, Poirier LA (1984) In vitro cadmium-DNA interactions cooperativity of cadmium binding and competitive antagonism by calcium, magnesium, and zinc. Toxicol Appl Pharmacol 75 539-546... 

Gabbiani, G., BaiC D. and Deziel C. (1967) Studies on tolerance and ionic antagonism for cadmium and mercury. Can. J. Physiol. Pharmacol 45, 443-450. 

Evans, G. W., Majors, P. F., and Comatzer, W. E., 1970, Mechanism of cadmium and zinc antagonism of copper metabolism, Biochem. Biophys. Res. Commun. 40 1142. 

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