Heavy metals teratogenic effects

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). 

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). 

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... 

Very many chemicals are recognized teratogens in animals a significantly smaller subset of these is known or suspected to be developmental neurotoxicants in humans. Some of the more significant of the latter group include ethanol, which causes a constellation of effects ranging from fetal alcohol syndrome to alcohol-related neurodevelopmental disorder maternal smoking of tobacco (fetal tobacco syndrome) excess vitamins A and D heavy metals, particularly... 

Ethyl alcohol is found in alcoholic beverages and is a known teratogenic material, which is the reason doctors tell pregnant women not to drink alcohol. When a mother drinks, the unborn child drinks as well. Ethyl alcohol causes growth failure and impaired brain development. Unborn children exposed to alcohol may suffer the effects of Eetal Alcohol Syndrome when they are bom. Symptoms of Fetal Alcohol Syndrome include sleep disturbance, jitteriness, a higher incidence of impaired vision and hearing, lack of motor coordination, balance problems, abnormal thyroid function, and a decrease in immune system effectiveness. Additional teratogens include heavy metals, methyl mercury, mercury salts, lead, thallium, selenium, penicillin, tetracyclines, excess Vitamin A, and carbon dioxide. 

Hurley LS, Gowan J, Swenerton H (1971) Teratogenic effects of short-term and transitory zinc deficiency in rats. Teratology 4 199-204 Karin M, Slater EP, Herschman HR (1981) Regulation of metallothionein synthesis in HeLa cells by heavy metals and glucocorticoids. J Cell Physiol 106 63-74 Karp B, Robertson AF (1981) Cadmium, the placenta, and the infant. In Nriagu JO (ed) Cadmium in the environment, part II, health effects. Wiley, New York, pp 729-742... 

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