Nitric oxide-dependent vasorelaxation and endothelial cell damage caused by mercury chloride.
Mercury and its derivatives are known to constrict vascular smooth muscle cells. However, little is known about the role of endothelial cells in mercury-induced vasoreactivity. Using isolated, norepinephrine preconstricted rat aorta and pulmonary artery rings with intact endothelium, we demonstrate that mercury chloride (HgCl2) induces an endothelial-dependent vasorelaxation which was totally blocked by the nitric oxide inhibitor L-NAME. Besides this vasorelaxant effect, treatment with HgCl2 resulted in functional and morphological alterations of the endothelial cells. On aortic rings, endothelial cells were partly lifted from the basal membrane when incubated for 20 min in HgCl2 (10(-7) M)-containing buffer. At a concentration of 10(-6) M, the endothelial cells were completely denuded and acetylcholine vasorelaxation was abolished. Endothelial cell structure and function was preserved by incubating the vessels in HgCl2-containing rat blood instead of buffer. We conclude that HgCl2 induces an endothelial-dependent vasorelaxation and alters structure and function of vascular endothelial cells.
Department of Internal Medicine, Philipps University of Marburg, Baldinger Strasse, 35033 Marburg, Germany. heiko.golpon@medizin.uni-magdeburg.de
Heiko A
HA
Golpon
Annette
A
Püchner
Peter
P
Barth
Tobias
T
Welte
Peter v
Pv
Wichert
Christian O
CO
Feddersen
D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D042783:Endothelial Cells / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D008627:Mercuric Chloride / Q000633:toxicity*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D011651:Pulmonary Artery / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014664:Vasodilation / Q000187:drug effects*
D004791:Enzyme Inhibitors; D008627:Mercuric Chloride; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester