Peng S, Shan X Q, Zheng Y, Jin L Z, Xu W B
Research Center for Eco-Environmental Sciences, Academia Sinica, Beijing, China.
J Chromatogr. 1991 Dec 6;572(1-2):73-84.
A rapid method is described for the determination of dietary cadmium-induced metallothioneins (MTs) in rabbit kidneys by anion-exchange high-performance liquid chromatography. Rabbit kidney MT-I and MT-II were eluted at ca. 15.0 and 18.8 min, respectively, from a DEAE-5PW anion-exchange column with a Tris-HCl buffer (0.01-0.25 M, pH 8.6) and detected by ultraviolet absorbance at 254 nm. A standard calibration curve was constructed using purified standard MT isoforms, which demonstrated an excellent linear correlation between UV absorbance peak heights and the amounts of MT isoforms. Feeding a dose of cadmium for some days resulted in an increase in MT concentrations in rabbit kidneys, but not in the livers. The cadmium concentrations in MT-I and MT-II elutions were determined by graphite furnace atomic absorption spectrometry. MT-I and MT-II showed some differences associated with the oral intake of cadmium. Dietary cadmium also caused zinc to accumulate in kidneys to some extent. The effects of dietary oleic acid on the synthesis of MTs were also studied. Based on the method of standard additions, the recovery of MTs exceeded 93% and replicated injection of samples yielded a relative standard deviation of 2.4% at an MT level of 280 micrograms/g.
本文描述了一种通过阴离子交换高效液相色谱法快速测定兔肾中膳食镉诱导的金属硫蛋白（MTs）的方法。兔肾MT-I和MT-II分别在约15.0分钟和18.8分钟从DEAE-5PW阴离子交换柱上洗脱，洗脱液为Tris-HCl缓冲液（0.01 - 0.25 M，pH 8.6），并通过254 nm处的紫外吸光度进行检测。使用纯化的标准MT同工型构建标准校准曲线，该曲线表明紫外吸光度峰高与MT同工型含量之间具有良好的线性相关性。连续数日喂食一定剂量的镉会导致兔肾中MT浓度升高，但肝脏中则不会。通过石墨炉原子吸收光谱法测定MT-I和MT-II洗脱液中的镉浓度。MT-I和MT-II在镉的口服摄入量方面表现出一些差异。膳食镉还会使锌在肾脏中积累到一定程度。同时还研究了膳食油酸对MTs合成的影响。基于标准加入法，MTs的回收率超过93%，在MT水平为280微克/克时，样品重复进样的相对标准偏差为2.4%。
