TY - JOUR
T1 - Metal transporters in intestine and brain
T2 - Their involvement in metal-associated neurotoxicities
AU - Bressler, Joseph P.
AU - Olivi, Luisa
AU - Jae, Hoon Cheong
AU - Kim, Yongbae
AU - Maerten, Alex
AU - Bannon, Desmond
PY - 2007/3
Y1 - 2007/3
N2 - The transport of essential metals and other nutrients across tight membrane barriers such as the gastrointestinal tract and blood-brain barrier is mediated by specific transport mechanisms. Specific transporters take up metals at the apical surface and export them at the basolateral surface, and are involved in their intracellular distribution. Transporters for each of the major essential metals, calcium, iron and zinc, have been identified. These transporters also mediate the transport of non-essential metals across tight membrane barriers. For example, the intestinal iron transporter divalent metal transporter 1 mediates the uptake of lead and cadmium. The levels of essential metals are strictly regulated by transporters. When dietary levels of essential metals are low, levels of the corresponding transporters increase in the intestine, after which there is a greater potential for increased transport of toxic metals. In the brain, the strict regulation of metals prevents injury that potentially would result from oxidative damage induced by the essential metals iron, copper and zinc. Indeed, the oxidative damage found in neurodegenerative diseases is likely to be due to higher levels of these metals. Involvement of intracellular transporters for copper and zinc has been shown in animal models of Alzheimer's disease, raising the possibility that higher levels of iron, zinc and copper might be due to a disruption in the activity of transporters. Accordingly, exposure to toxicants that affect the activity of transporters potentially could contribute to the aetiology/progression of neurodegenerative diseases.
AB - The transport of essential metals and other nutrients across tight membrane barriers such as the gastrointestinal tract and blood-brain barrier is mediated by specific transport mechanisms. Specific transporters take up metals at the apical surface and export them at the basolateral surface, and are involved in their intracellular distribution. Transporters for each of the major essential metals, calcium, iron and zinc, have been identified. These transporters also mediate the transport of non-essential metals across tight membrane barriers. For example, the intestinal iron transporter divalent metal transporter 1 mediates the uptake of lead and cadmium. The levels of essential metals are strictly regulated by transporters. When dietary levels of essential metals are low, levels of the corresponding transporters increase in the intestine, after which there is a greater potential for increased transport of toxic metals. In the brain, the strict regulation of metals prevents injury that potentially would result from oxidative damage induced by the essential metals iron, copper and zinc. Indeed, the oxidative damage found in neurodegenerative diseases is likely to be due to higher levels of these metals. Involvement of intracellular transporters for copper and zinc has been shown in animal models of Alzheimer's disease, raising the possibility that higher levels of iron, zinc and copper might be due to a disruption in the activity of transporters. Accordingly, exposure to toxicants that affect the activity of transporters potentially could contribute to the aetiology/progression of neurodegenerative diseases.
KW - Brain
KW - Disease
KW - Intestine
KW - Metals
KW - Transporters
UR - http://www.scopus.com/inward/record.url?scp=33947371597&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33947371597&partnerID=8YFLogxK
U2 - 10.1177/0960327107070573
DO - 10.1177/0960327107070573
M3 - Article
C2 - 17439925
AN - SCOPUS:33947371597
SN - 0960-3271
VL - 26
SP - 221
EP - 229
JO - Human and Experimental Toxicology
JF - Human and Experimental Toxicology
IS - 3
ER -