Mercury- and lead-induced contraction of aortic smooth muscle in vitro.
Mercuric chloride and lead acetate caused contraction of rabbit aortic segments in vitro. Mercuric chloride was added to a Krebs Henseleit solution; lead acetate was added to a Tris-buffered medium to avoid any precipitation of lead. Cadmium (Cd++) acetate, in either medium, had no direct effect. The Hg++- and Pb++-induced contractions were significantly reduced when Ca++ was omitted from the physiological buffer or when pH decreased. The alkylated analogues of Hg++ and Pb++ salts had little direct contractile effect. However, segments exposed to these analogues lost their ability to respond to other agonists. This report provides evidence that Hg++ and Pb++ can directly induce active tension by action on processes which rely on extracellular Ca++.
D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D002118:Calcium / Q000502:physiology; D005260:Female; D066298:In Vitro Techniques; D007854:Lead / Q000494:pharmacology*; D008628:Mercury / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009942:Organometallic Compounds / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011817:Rabbits
D009942:Organometallic Compounds; D007854:Lead; D008628:Mercury; D011188:Potassium; D002118:Calcium