Role Of ALAD In Lead Toxicology - Essay Example

Role of ALAD in lead toxicology Lead is a persistent and common environmental contaminant. Lead damages cellular material and alters cellular genetics leading to neurological, hematological, gastrointestinal, reproductive, circulatory, and immunological pathologies. The mechanism of lead toxicity involves oxidative damage by producing reactive oxygen species which inhibit inhibit the production of sulfhydryl antioxidants, inhibit enzyme reactions impairing heine production, cause inflammation in vascular endothelial cells, damage nucleic acids and inhibit DNA repair, and initiate lipid peroxidation in cellular membranes (Lyn Patrick, 2006).

A safe level of lead exposure has not been defined, as health risks associated with lead are found at ever lower doses. The toxicity of lead is due to its property to mimic other biologically essential metals, like calcium, iron and zinc (Onalaja & Claudio, 2000). It has been observed that lead binds to enzymes that have functional sulfhydryl groups, rendering them nonfunctional and further contributing to impairment in oxidative balance. Levels of two specific sulfhydryl-containing enzymes that are inhibited by lead are delta-aminolevulinic acid dehydrogenase (ALAD) and glutathione reductase (GR) which has been demonstrated to be depressed in both animal and human lead-exposure studies (Lyn Patrick, 2006).

Polymorphisms of the ALAD gene have been associated with the accumulation and distribution of lead in the blood, bone, and internal organs in humans and animals. Lead binds with and interacts with the same proteins and molecules, and interferes in normal activity of molecules, such as in producing enzymes necessary for certain biological processes. Like it interferes with an essential enzyme Delta-aminolevulinic acid dehydratase, or ALAD. ALAD is a zinc-binding protein which is important in the biosynthesis of heme, the cofactor found in hemoglobin.

Lead binds with ALAD and causes disruption in its normal functioning. Works Cited Ahamed, M., Verma, S., Kumar, A., & Siddiqui, M. (2005). Environmental exposure to lead and its correlation with biochemical indices in children. Sci Total Environ , 346, 48-55. Farant, J., & Wigfield, D. (1982). Biomonitoring lead exposure with delta-aminolevulinate dehydratase (ALA-D) activity ratios. Int Arch Occup Environ Health 1982 , 51, 15-24. Gurer-Orhan, H., Sabir, H., & Ozgunes, H. (2004). Correlation between clinical indicators of lead poisoning and oxidative stress parameters in controls and lead-exposed workers.

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