Evis M J, Dhaliwal K, Kane K A, Moore M R, Parratt J R
Arch Toxicol. 1987 Feb;59(5):336-40. doi: 10.1007/BF00295086.
The aim of this study was to investigate whether chronic (3 months) lead (250 or 1000 ppm), administered as lead acetate in the drinking water, commencing either after weaning (in normotensive or spontaneously hypertensive male rats) or from conception (normotensive rats only) altered the susceptibility of the heart to arrhythmias induced either by coronary artery occlusion or by noradrenaline. Treatment with lead alone had no marked effect on the arrhythmias elicited by either method. Spontaneously hypertensive rats treated with either dose of lead exhibited more ectopic beats following coronary artery occlusion than normotensive rats but not more than those observed in control spontaneously hypertensive rats. An enhanced arrhythmogenic effect of noradrenaline was observed only in hypertensive rats administered 250 ppm lead. Both doses of lead accelerated the development of high blood pressure and in normotensive rats the higher dose also resulted in an elevated pressure. Following administration of lead, blood lead concentrations were elevated to 0.96 and 2.11 mumol l-1 after 250 and 1000 ppm, respectively. Accumulation of lead in heart and bone was also observed. We conclude that chronic exposure to these concentrations of lead, when combined with high blood pressure, slightly enhances the susceptibility of the heart to arrhythmias induced by myocardial ischaemia.
本研究的目的是调查，以醋酸铅形式通过饮用水给予大鼠慢性（3个月）铅暴露（250或1000 ppm），在断奶后（正常血压或自发性高血压雄性大鼠）或从受孕开始（仅正常血压大鼠），是否会改变心脏对冠状动脉闭塞或去甲肾上腺素诱导的心律失常的易感性。单独用铅治疗对两种方法诱发的心律失常均无明显影响。用任一剂量铅治疗的自发性高血压大鼠在冠状动脉闭塞后出现的异位搏动比正常血压大鼠多，但不超过对照自发性高血压大鼠。仅在给予250 ppm铅的高血压大鼠中观察到去甲肾上腺素的致心律失常作用增强。两种剂量的铅均加速了高血压的发展，在正常血压大鼠中，较高剂量也导致血压升高。给予铅后，250 ppm和1000 ppm时血铅浓度分别升高至0.96和2.11 μmol l-1。还观察到铅在心脏和骨骼中的蓄积。我们得出结论，长期暴露于这些浓度的铅，与高血压相结合时，会轻微增强心脏对心肌缺血诱导的心律失常的易感性。
