镉的生物学作用

• 作 者: 史济德 倪云
• 出 处: 国外医学参考资料(卫生学分册)
• 发表日期: 1977年06期
• 关键词: 原发性高血压 大鼠血压 美国居民 收缩作用 双重效应 大鼠 微量元素 动物实验 肾脏 浓度

镉是普遍存在的微量元素,每个人经常接触它。通常,美国居民一生平均可蓄积30毫克的镉。近来认为,低浓度长期接触镉可伴发高血压,但有关镉与高血压之间联系的证据均来自动物实验。使大鼠长期进食低剂量的镉,模拟人类的接触量,可导致动脉压轻度或中度升高,类似于人类的(与镉无关联的)原发性高血压。镉引起大鼠血压升高的机制尚不清楚;曾有报导,镉可导致双重效应,它既能使肾脏钠潴留亦可直接对血管平滑肌起收缩作用,从而使血压升高。

Cadmium is a ubiquitous trace element, and everyone often comes into contact with it. Typically, U.S. residents accumulate 30 mg of cadmium on average over their lifetime. Recently, low concentrations of long-term exposure to cadmium may be associated with hypertension, but the evidence for the link between cadmium and hypertension are from animal experiments. Long-term consumption of low doses of cadmium in rats, simulating human exposure, can lead to mild or moderate arterial hypertension, similar to the human (with cadmium-unrelated) essential hypertension. Cadmium-induced hypertension in rats is unclear; it has been reported that cadmium can cause a double effect, which not only renders the kidneys sodium retention but also directly contracts the vascular smooth muscle, resulting in increased blood pressure.