Murakami M, Tohyama C, Sano K, Kawamura R, Kubota K
Arch Toxicol. 1983 Jul;53(3):185-92. doi: 10.1007/BF00316502.
The renal distribution of 125I-labelled metallothionein (125I-MT), administered as a tracer dose to female Wistar rats, has been investigated by light and electron microscopical autoradiography. 125I-MT was absorbed rapidly and 80% of the administered dose was observed in the kidney within 60 min after dosing. At 30 min, a high density of silver grains due to 125I, was observed by light microscopy in the convoluted proximal tubules. Electron microscopical autoradiography showed that silver grains were located in large apical vacuoles and cytoplasmic bodies (heterolysosomes) of the endocytotic system in the apical or middle regions of the cells lining convoluted proximal tubules. The results suggest that endocytotic systems are associated with 125I-MT absorption by epithelial cells lining the renal convoluted proximal tubules. The apparent inconsistency on the distribution pattern of silver grains due to 109Cd-labelled MT and 125I-labelled MT in these is also discussed.
给雌性Wistar大鼠注射示踪剂量的¹²⁵I标记金属硫蛋白（¹²⁵I-MT）后，通过光学显微镜和电子显微镜放射自显影术研究了¹²⁵I-MT在肾脏中的分布。¹²⁵I-MT吸收迅速，给药后60分钟内，在肾脏中观察到80%的给药剂量。给药30分钟时，光学显微镜下在近曲小管中观察到由于¹²⁵I导致的高密度银颗粒。电子显微镜放射自显影显示，银颗粒位于近曲小管内衬细胞顶端或中部区域内吞系统的大顶端液泡和细胞质体（异溶酶体）中。结果表明，内吞系统与肾近曲小管内衬上皮细胞对¹²⁵I-MT的吸收有关。还讨论了¹⁰⁹Cd标记的MT和¹²⁵I标记的MT在这些细胞中银颗粒分布模式上明显的不一致性。
