Skoczynska A, Skórka T, Wojakowska A, Nowacki D, Turczyn B, Poręba R, Tyrankiewicz U, Byk K, Szuba A
1Department of Internal and Occupational Diseases, Wroclaw Medical University, Wrocław, Poland.
Hum Exp Toxicol. 2014 May;33(5):455-65. doi: 10.1177/0960327113491507. Epub 2013 Jun 11.
The aim of this study was to evaluate the effect of lead (Pb)-contaminated drinking water on magnetic resonance imaging (MRI)-estimated cardiac function, vascular reactivity, and serum lipids in rats. For 3 months, male Wistar rats, aged 4-6 weeks, were given drinking water with the addition of lead acetate at a concentration of 100 ppm Pb (10 rats) or water free from Pb (8 control rats). The cardiac MRI was performed at rest and under β-adrenergic stimulation on a 4.7 T scanner using electrocardiogram-triggered gradient echo (FLASH) cine sequence. After 1-2 weeks of the MRI test, experiments were performed ex vivo. After stabilization of perfusion pressure (PP), norepinephrine at doses from 0.01 to 5.0 μg was dissolved in Krebs solution, injected in a volume of 100 μl, and next infused at a concentration of 0.5 μg/ml into the isolated mesenteric artery. In this manner, preconstricted mesenteric bed was used to determine PP changes induced by acetylcholine, given at doses from 0.05 to 5.0 μg, before and during the infusion of nitric oxide synthase inhibitor (1.0 μg/ml). At the end, dobutamine (5 mg), followed by potassium chloride (10.5 mg), was injected. Lipid levels were determined enzymatically, blood Pb level was measured by the atomic absorption spectrophotometer. This study showed that Pb impairs the left ventricular systolic and diastolic function. Pb-induced changes in response to resistance of vessels to vasoactive agents may be secondary to the reduced left ventricular ejection fraction. The high-density lipoprotein subfraction 2 (HDL2) is involved in the cardiovascular effect of Pb.
本研究旨在评估铅（Pb）污染的饮用水对大鼠磁共振成像（MRI）估计的心脏功能、血管反应性和血脂的影响。4至6周龄的雄性Wistar大鼠饮用添加了浓度为100 ppm Pb的醋酸铅的水3个月（10只大鼠），或饮用不含Pb的水（8只对照大鼠）。在4.7 T扫描仪上使用心电图触发的梯度回波（FLASH）电影序列，在静息状态和β-肾上腺素能刺激下进行心脏MRI检查。在MRI测试1至2周后，进行离体实验。在灌注压力（PP）稳定后，将剂量为0.01至5.0 μg的去甲肾上腺素溶解在 Krebs 溶液中，以100 μl的体积注射，然后以0.5 μg/ml的浓度注入离体肠系膜动脉。通过这种方式，在灌注一氧化氮合酶抑制剂（1.0 μg/ml）之前和期间，使用预收缩的肠系膜床来确定由剂量为0.05至5.0 μg的乙酰胆碱引起的PP变化。最后，注射多巴酚丁胺（5 mg），随后注射氯化钾（10.5 mg）。通过酶法测定血脂水平，用原子吸收分光光度计测量血铅水平。本研究表明，Pb会损害左心室的收缩和舒张功能。Pb引起的血管对血管活性药物反应的变化可能继发于左心室射血分数的降低。高密度脂蛋白亚组分2（HDL2）参与了Pb的心血管效应。
