Bischoff K
Illinois Institute of Technology, Chicago 60616, USA.
Vet Hum Toxicol. 2001 Oct;43(5):294-7.
Cyanobacterial blooms occur worldwide and present an increasing problem due to eutrophication of lakes. Microcystins, especially microcystin-LR, are microcyclic heptapeptide hepatotoxins and are the most common and potent toxins associated with cyanobacteria. Microcystin is rapidly taken up by hepatocytes through carrier-mediated transport. Once in the hepatocyte, microcystin causes structural damage to the cell indirectly by inhibiting protein phosphorylases 1 and 2A, which are needed for regulation of structural proteins of the cell. Acute liver hemorrhage and death occur with high doses of microcystin-LR, which is also a potent tumor promoter in laboratory rats. The significance of microcystin to human health has been debated; however, poisoning in humans has occurred due to contaminated dialysis water. Microcystin in contaminated drinking water may be the cause of elevated rates of primary liver cancer in some areas of China. Problems with hepatotoxic cyanobacteria have been most seen in livestock. Treatment of confirmed microcystin toxicosis in livestock is likely to be unrewarding, so prevention is important. Wild mammals, birds, fish, insects, and microinvertebrates may also be affected by microcystin.
蓝藻水华在全球范围内出现，并且由于湖泊富营养化问题日益严重。微囊藻毒素，尤其是微囊藻毒素-LR，是一种环状七肽肝毒素，是与蓝藻相关的最常见且毒性最强的毒素。微囊藻毒素通过载体介导的转运迅速被肝细胞摄取。一旦进入肝细胞，微囊藻毒素通过抑制细胞结构蛋白调节所需的蛋白磷酸酶1和2A间接对细胞造成结构损伤。高剂量的微囊藻毒素-LR会导致急性肝出血和死亡，它在实验大鼠中也是一种强效的肿瘤促进剂。微囊藻毒素对人类健康的重要性一直存在争议；然而，因透析水污染导致人类中毒的事件已经发生。受污染饮用水中的微囊藻毒素可能是中国某些地区原发性肝癌发病率升高的原因。肝毒性蓝藻问题在牲畜中最为常见。治疗已确诊的牲畜微囊藻毒素中毒可能收效甚微，因此预防很重要。野生哺乳动物、鸟类、鱼类、昆虫和微型无脊椎动物也可能受到微囊藻毒素的影响。
