Effects of CBMIDA(Catechol-3,6-bis(methyleiminodiacetic acid)) on Removal of Plutonium in Rats.

Abstract

Effects of CBMIDA [catechol-3, 6-bis(methyleiminodiacetic acid)] on injected 239Pu were examined in rats; in our previous studies, CBMIDA had almost the same toxicity as those of DTPA and EDTA. Rats were injected intravenously with 239Pu (1.85×104Bq/kg) and divided into four groups of five rats each. Three groups were each injected intraperitoneally with a daily dose of 150μmol/kg of CBMIDA, Ca-DTPA or Zn-DTPA for 2 weeks, beginning at about 1h after plutonium injection. Rats were sacrificed 14 days later and the femur and liver were removed. All excreta were collected at 24-h intervals during the experimental period. Plutonium contents of the femur, liver, feces and urine treated by a wet ashing method were measured by a liquid scintilation spectrometry.The plutonium contents in the skeleton of administered dose were 11.5% for CBMIDA group, 19.0% for Ca-DTPA group, and 26.9% for Zn-DTPA group, whereas that was 63.9% for the control; those in the liver were 0.62% for CBMIDA group, 0.35% for Ca-DTPA group and 0.54% for Zn-DTPA group, whereas that was 7.74% for the control. The data obtained indicate that CBMIDA is superior to Ca-DTPA and Zn-DTPA on removing plutonium from bone, and also has almost the same effectiveness on removing it from liver as those of both Ca-DTPA and Zn-DTPA. The higher effectiveness of CBMIDA on removal of plutonium from the skeleton might be, besides the stronger chelating action, due to the inhibition of plutonium deposition into bone, judging from the results of our previous study wherein the effects of CBMIDA on bone metabolism were examined in beagle dogs.In conclusion, taking together the results obtained in this study and those from our previous studies on the toxicity, it was demonstrated that CBMIDA could be utilized, as a new chelating agent, to remove plutonium from human body.