Endothelium: A Target for Harmful Actions of Metals

The use of heavy metals is closely linked to the history of mankind. They have been used as important materials in a wide variety of human activities such as manufacturing utensils and tools. Such extended use has significantly increased professional and environmental exposure to mercury, lead and cadmium. These metals are known to produce hypertension in humans and animals and, among other effects, they can also affect endothelial function. Results described here suggest that mercury, lead and cadmium affect vascular reactivity, even at low doses or concentrations. Several vascular actions are mediated by the endothelium via increasing the production of free radicals and angiotensin II by local ACE stimulation. These results provide further evidence that these toxic metals, even at low doses, are an environmental risk factor to the exposed population. These results also suggest that continuous exposure to these metals, followed by their absorption and progressive accumulation in the body, may be hazardous to cardiovascular function. Therefore, the current reference values, which are considered safe, need to be reduced.