Excretion of cadmium through bile and intestinal wall in rats

Abstract

of cadmium through bile and intestinal wall in rats. The excretion of Cd2+ through the bile and intestinal wall after intravenous administration of CdC12 in non-toxic doses (67, 90, and 120 ,ug of Cd2+ per rat) was studied in rats. The cumulative biliary excretion reached 24 hours after administration of the 67 jug dose was 0 83 %, after 90 jig 1-18 %, and after the 120 ,tg dose 5-68 % of the amount given. The highest excretion rate of Cd2+ was detected between 15 and 30 minutes after administration. There was no difference in the excretion through intestinal wall between the 67 and 120 ,ug doses of Cd2+ per rat. The mean amount of cadmium found in the contents of the entire gastrointestinal tract and faeces was 5-5 % of the administered dose. Using polyacrylamide gel disc electrophoresis it was found that Cd2+ is bound with at least two different components of the rat bile.

Biliary excretion of cadmium.

“…The relative excretion of cadmium in bile in percent of body burden of cadmium, as measured by whole body counting, was the same in both groups of rats, independent of the total administered cadmium dose. This finding is not in accordance with acute exposure studies, where higher dose levels have been shown to give a higher relative excretion (8,13,14) but does agree with the metabolic model of cadmium metabolism in humans proposed by Kjellstrom and Nordberg (26), and with empirical data from humans where cadmium levels in bile on group basis are related to liver concentrations of cadmium (23).…”

“…Biliary excretion of cadmium directly after a parenteral dose has been measured in rats by a number of authors (8,(12)(13)(14)(15)(16)(17)(18). Such studies have shown that initially the excretion of cadmium via bile is high.…”

Teratogenicity, Toxicity and Perinatal Effects of Cadmium

“…Cikrt & Tichy (1974) have shown a dose-dependent excretion in the bile of between 0.8 and 5.7% of an intravenous pulse of cadmium. Finally cadmium is also excreted via skin, hair, sweat, nails and saliva but these routes are considered to be of only minor importance (CEC, 1978).…”

Defense mechanisms against cadmium toxicity. II. Effects of pretreatment with a small oral dose of cadmium on absorption, distribution and excretion of cadmium after a large oral dose in mice.

“…Within 24 hr after administration of Cd2+ to rats (67 fig Cd2+/rat, i.v. ), 0.83% of the dose is excreted in the bile and 5.31% in the entire gastrointestinal tract and feces (12). Approximately 10% of the administered dose (1 mg Cd2+/ kg, i.v.)…”

“…administration of the cation to rats is the gastrointestinal tract (11)(12)(13). Within 24 hr after administration of Cd2+ to rats (67 fig Cd2+/rat, i.v.…”