Biochemical Pathways of Heavy Metal Poisoning
Biochemical Pathways of Heavy Metals Poisoning
BIO101 (Principles of Biology)
6 July 2012
Abstract
The biochemical pathways of heavy metal poisoning are routes by which the metals pass in the body as they impair and destroy normal cellular and organ activity. The most common types of heavy metal poisoning are caused by lead, arsenic, cadmium and mercury. They are also the most extensively studied at the moment. Lead poisoning occurs mainly by the inhibitory effect that the metal imposes on enzymes and subsequent distortion of essential biochemical pathways. The metal disrupts calcium metabolism and subsequently causes neurotoxicity. It also inhibits the reduction of glutathionine in a biochemical process meant to produce antioxidants. Lead also intrudes and redirects the heme synthesis pathway leading to build up of aminolevulinic acid (ALA) in the cell. This results in the production of Reductive Oxygen Species (ROS) that mediate cell injury. Arsenic poisoning leads to the impairment of intracellular and intercellular communication pathways. Its effect on signal transduction leads to build up of free radicals that mediate cell death or injury. Mercury poisoning results from methylmercury. It has inhibitory effects that resemble those of lead and uniquely induces the release of free radicals in cells.
Cadmium mainly poisons the cell by displacing essential nutrients such as calcium, zinc, iron and copper from biomolecules. The displaced metals are precipitated in body fluids and tissues and may be excreted or accumulate in the body. The biochemical pathways by which metal poisoning occurs mainly involve inhibition of biosynthetic, regulatory and other forms of enzyme activities, altered signal transduction pathways, induction of the production of free radicals and displacement biochemical reactions.
Biochemical Pathways of Heavy Metals Poisoning
Heavy metal poisoning is one of the most devastating health hazards that stems from environmental pollution.
BIO101 (Principles of Biology)
6 July 2012
Abstract
The biochemical pathways of heavy metal poisoning are routes by which the metals pass in the body as they impair and destroy normal cellular and organ activity. The most common types of heavy metal poisoning are caused by lead, arsenic, cadmium and mercury. They are also the most extensively studied at the moment. Lead poisoning occurs mainly by the inhibitory effect that the metal imposes on enzymes and subsequent distortion of essential biochemical pathways. The metal disrupts calcium metabolism and subsequently causes neurotoxicity. It also inhibits the reduction of glutathionine in a biochemical process meant to produce antioxidants. Lead also intrudes and redirects the heme synthesis pathway leading to build up of aminolevulinic acid (ALA) in the cell. This results in the production of Reductive Oxygen Species (ROS) that mediate cell injury. Arsenic poisoning leads to the impairment of intracellular and intercellular communication pathways. Its effect on signal transduction leads to build up of free radicals that mediate cell death or injury. Mercury poisoning results from methylmercury. It has inhibitory effects that resemble those of lead and uniquely induces the release of free radicals in cells.
Cadmium mainly poisons the cell by displacing essential nutrients such as calcium, zinc, iron and copper from biomolecules. The displaced metals are precipitated in body fluids and tissues and may be excreted or accumulate in the body. The biochemical pathways by which metal poisoning occurs mainly involve inhibition of biosynthetic, regulatory and other forms of enzyme activities, altered signal transduction pathways, induction of the production of free radicals and displacement biochemical reactions.
Biochemical Pathways of Heavy Metals Poisoning
Heavy metal poisoning is one of the most devastating health hazards that stems from environmental pollution.
References: Kitchin, K. T., and Wallace, K. (2008). Evidence against the nuclear in situ binding of arsenicals—oxidative stress theory of arsenic carcinogenesis. Toxicol. Appl. Pharmacol. Ogwuegbu MO, Ijioma MA (2003). Effects Of Certain Heavy Metals On The Population Due To Mineral Exploitation. International Conference on Scientific and Environmental Issues In The Population, Environment and Sustainable Development in Nigeria, University ofAdo Ekiti, Ekiti State, Nigerian, pp. 8-10. Swaran J.S. Flora and Vidhu Pachauri (2010). Chelation in Metal Intoxication. International Journal of Environmental Research and Public Health.