摘要:

Biliary excretion of cadmium was studied in rats after intravenous injection of different doses of cadmium chloride (0.1–2 mg Cd/kg). The rate of bile flow was not affected by cadmium injection and cadmium was excreted into bile during the first 2 hr after injection. The biliary excretion of cadmium increased with increasing dose of CdCl1. Cumulative biliary excretion of cadmium for 5 hr was 0.065% of the administered dose for groups injected with 0.1 mg Cd/kg as compared to 16.9% of the administered dose for 2 mg Cd/kg. During the 5 hr experimental period, most of the cadmium in liver cytosol was bound to high‐molecular‐weight proteins and less than 10% was bound to the metallothionein fraction. The biliary cadmium was recovered as a low‐molecular‐weight compound (less than 4,000) in experiments with various doses of cadmium and no cadmium was attached to high‐molecular‐weight proteins or metallothionein in the bile. The low‐molecular‐weight cadmium complex in bile was partially characterized as Cd‐glutathione by thin‐layer chromatography and amino acid analysis.

ISSN:0098-4108    

DOI:10.1080/15287397709529493

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Intravenous injection of109Cd‐labeled CdCI2(I mg/kg) to control rats and rats that had been injected with CdCI2(0.25 mg/kg) 24 hr earlier showed that there was a decrease in the biliary excretion of109Cd in the latter group. The 24 hr pretreatment with CdCI2resulted in induced synthesis of metallothionein in rat liver and kidney. The binding of cadmium to liver tissue was increased and the renal accumulation of cadmium was unaltered on cadmium pretreatment.

ISSN:0098-4108    

DOI:10.1080/15287397709529494

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

In protecting the body against the noxious effects of dietary cadmium ions, cadmium is bound to metallothionein in the proximal intestine, and subsequently excreted into the lumen with desquamation of the epithelium. The purpose of this study was to determine the extent to which cadmium in the form of intestinal cadmium‐thionein is absorbed from the intestinal lumen and to appraise the toxicity of cadmium‐thionein on the intestinal mucosa. With open‐ended duodenal perfusion, equivalent amounts of cadmium administered as CdCl2or cadmium‐thionein entered the mucosa, but significantly less cadmium from the perfusate of cadmium‐thionein passed into the body. Exposure of the mucosa to CdCl2for 1 hr led to minor abnormalities in the form of broadening of villi with pseudostratification of epithelium, and swelling of mitochondria, whereas cadmium‐thionein produced extensive necrosis of absorptive cells. The results suggest that cadmium‐thionein may play a paradoxical role, providing protection against the cadmium ion in the intracellular milieu, but promoting cadmium toxicity when it is present in sufficient amounts in the lumen of the intestine.

ISSN:0098-4108    

DOI:10.1080/15287397709529495

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

ISSN:0098-4108    

DOI:10.1080/15287397709529472

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor