Metals teratogenicity

The amino acids L-leucine, T-phenylalanine, L-tyrosine, and L-tryptophan all taste bitter, whereas their D-enantiomers taste sweet (5) (see Amino ACIDS). D-Penicillamine [52-67-5] a chelating agent used to remove heavy metals from the body, is a relatively nontoxic dmg effective in the treatment of rheumatoid arthritis, but T.-penicillamine [1113-41 -3] produces optic atrophy and subsequent blindness (6). T.-Penicillamine is roughly eight times more mutagenic than its enantiomer. Such enantioselective mutagenicity is likely due to differences in renal metaboHsm (7). (R)-ThaHdomide (3) is a sedative—hypnotic (3)-thaHdomide (4) is a teratogen (8). 

Grossly elevated concentrations of dissolved copper produce teratogenicity in fish embryos. A significant number of malformed fish larvae came from eggs treated with 500 pg Cu/L (Birge and Black 1979). In studies with laboratory animals and elevated concentrations of copper salts, copper penetrates the placental barrier into the fetus intramuscular injection of 4 mg Cu/kg BW early in pregnancy adversely affects fetal central nervous system development (Aaseth and Norseth 1986). In humans, no definitive data are available on whether copper can cause birth defects however, incubation of human spermatozoa with metallic copper results in loss of sperm motility (Aaseth and Norseth 1986). 

Earl, F.L. and T.J. Vish. 1979. Teratogenicity of heavy metals. Pages 617-639 in F.W. Oehme (ed.). Toxicity of Heavy Metals in the Environment. Part 2. Marcel Dekker, New York. 

Tellurium is not an essential element, and tellurium compounds are in general more toxic than their selenium counterparts. Metallic tellurium is known to have a teratogenic effect in rats, though no studies have been done on the toxicity of tellurium donor compounds (35). 

A book of interest is "Chemically Induced Birth Defects," by Schardein (ref. 6). This reference book contains data on human and animal studies on birth defects and teratogens. Drugs are covered extensively. Chemicals discussed are pesticides, metals, industrial solvents, diagnostic agents, dyes, radioactive chemicals, plastics, toxins, food additives, air-water-soil pollutants, personal chemicals, etc. 

Mutagenicity, carcinogenicity, and teratogenicity of industrial pollutants are discussed in a book edited by Kirsh-Volders (ref. 9) The pollutants covered are metals, insecticides, various industrially important monomers and halogenated hydrocarbon solvents. 

Since the concern of this monograph is teratogens, the effects of chemicals on sperm and male reproduction are not dealt with. However, for readers interested in the latter a recent review article by Schrag and Dixon, "Occupational Exposures Associated with Male Reproductive Dysfunction" (ref. 20)is recommended. Chapters on various aspects of male reproductive toxicology and on sperm production of men working under heavy-metal or organic-solvent exposure are presented by Hemminki et al. (ref. 19). 

Mutagenicity, Carcinogenicity, and Teratogenicity of Industrial Pollutants (ref. 15) contains summaries of teratogenicity information about industrial pollutants. Discussions of these pollutants are divided into four groups heavy metals, insecticides, monomers, and halogenated hydrocarbon solvents. 

Table 1 lists two common metals, lead and mercury. The highly teratogenic organic compounds of these metals are not ordinarily handled in the undergraduate laboratory. Inorganic salts of lead and mercury are discussed in the next section. It is only the free elements that are addressed here. 

Several studies indicate that different methods cause adverse effects to embryonic and fetal tissues and eventually lead to the development of teratogenic effects. Metals are omnipresent in the living environment. A variety of anthropogenic activities (e.g., smelting metallic ore, industrial and metal fabrication, commercial application, burning of fossil fuels) have caused adverse effects to the developing fetus. In fact, notorious elements, such as cadmium, lead, and mercury, have been associated with injury and malformation to the growing embryo and fetus of animals and humans.65... 

V.H. Ferm, The teratogenic effects of metals on mammalian embryos. Adv. Teratol. 6 51-75, 1972. 

Calevro F, Campani S, Ragghianti M, et al. 1998. Tests of toxicity and teratogenicity in biphasic vertebrates treated with heavy metals (CR3+, AL3+, Cd2+). Chemosphere 37(14-15) 3011-3017. 

Several heavy metals have been identified as teratogens and possible abortifacients in humans and animals, and the adverse effects of prenatal lead exposure on the developing nervous systems of both human and laboratory animal species have been well documented (Evans et al, 2003 Rice, 1998 Rogers and Kavlock, 2008). Prenatal exposure to organotins has been associated with pregnancy loss and... 

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