Koyama H, Satoh H, Suzuki S, Tohyama C
Department of Environmental Health Sciences, Tohoku University School of Medicine, Sendai, Japan.
Arch Toxicol. 1992;66(8):598-601. doi: 10.1007/BF01973392.
To assess the renal effects of low-level exposure to cadmium due to smoking we examined blood and urinary levels of cadmium and urinary excretions of N-acetyl-beta-D-glucosaminidase (NAG), beta 2-microglobulin (BMG) and metallothionein in 94 male workers aged 18-55 years. Both blood and urinary cadmium levels indicated excess exposure to cadmium caused by smoking. The urinary cadmium concentration ranged between 0.1 and 5.0 micrograms/g creatinine and increased significantly with age in the smokers. Neither urinary NAG nor BMG was increased in the smokers compared from non-smokers. A positive relationship between urinary cadmium and metallothionein was obtained not only in the smokers but also in the non-smokers. Furthermore, in the smokers urinary cadmium and metallothionein was positively related with urinary NAG. Since NAG in urine mostly originates from tubular cells by lysosomal exocytosis, the results may reflect an early cadmium effect on the lysosomal functions. Inhibitory effect of cadmium on the lysosomal degradation activities was discussed as a possible explanation of the positive relationship of urinary cadmium and metallothionein to urinary NAG.
为评估吸烟导致的低水平镉暴露对肾脏的影响，我们检测了94名年龄在18至55岁之间的男性工人的血液和尿液中的镉含量，以及尿液中N - 乙酰 - β - D - 氨基葡萄糖苷酶（NAG）、β2 - 微球蛋白（BMG）和金属硫蛋白的排泄情况。血液和尿液中的镉含量均表明吸烟导致镉暴露过量。吸烟者尿液中镉浓度在0.1至5.0微克/克肌酐之间，且随年龄显著增加。与不吸烟者相比，吸烟者尿液中的NAG和BMG均未增加。不仅在吸烟者中，而且在不吸烟者中，尿液镉与金属硫蛋白之间均呈正相关。此外，在吸烟者中，尿液镉和金属硫蛋白与尿液NAG呈正相关。由于尿液中的NAG大多通过溶酶体胞吐作用源自肾小管细胞，这些结果可能反映了镉对溶酶体功能的早期影响。镉对溶酶体降解活性的抑制作用被讨论为尿液镉和金属硫蛋白与尿液NAG呈正相关的一种可能解释。
