Lead-induced hypertension: possible role of endothelial factors.

The results of this study confirm that low lead (0.01%) but not high lead (0.5%) administration results in increased blood pressure in rats treated for up to 12 months. This effect appeared to be related to an imbalance of endothelially-derived vasoconstrictor and vasodilator compounds in low lead-treated animals but not in high lead-treated animals. In low lead-treated rats, measurement of plasma endothelins 1 and 3 (ET-1 and ET-3) revealed that ET-3 concentration increased significantly after both 3 months (Experimental, 92.1±9.7 υ Control, 46.7±12.0 pmol/mL; P<.001) and 12 months (Experimental, 105.0±9.3 υ Control, 94.1±5.0 pmol/mL; P<.01) while ET-1 was unaffected