[Lead Effect on Vascular Endothelium]

The results of numerous epidemiological and experimental studies show that environmental exposure to lead in humans, as well as small doses of this element given to experimental animals exert hypertensinogenic and athoregenic effect. The vascular endothelium, involved in the development of arterial hypertension and arteriosclerosis, is now regarded as the main target organ for the toxic effect of lead. This metal can influence endothelium in various ways. Functional disturbances, mainly in respect of synthesizing and modifying functions of intravascular coagulation processes, impairment of endothelium integrity and cytotoxic effect have been observed. The lead-induced vascular damage may involve the inhibition of the repair processes of endothelial cells damaged by various exo- and endogenous factors. In addition, lead can also affect, directly or indirectly, the vasoactive function of endothelium through the increased production of reactive oxygen species. This effect of lead results in modified nitric oxide or endothelin synthesis and/or their release. Lead also accelerates the proliferation of smooth muscle cells and disturbs the synthesis of prostacyclins.