Efficacies of manganese chloride and Ca-DTPA (calcium diethylenetriaminepentaacetic acid) for the elimination of incorporated 54Mn were investigated in mice. Each mouse was given an intraperitoneal injection of 54Mn and initial whole-body radioactivity was measured immediately. Manganese chloride (10mg-Mn/kg) or Ca-DTPA (10 or 100mg/kg) was injected intraperitoneally once or repeatedly at various times after 54Mn injection. Efficacies for elimination were estimated by measuring the whole-body retention of 54Mn for 14 or 21 days.
A single injection of manganese chloride eliminated more than 80% of the incorporated 54Mn when it was injected within 24h after the injection of 54Mn. Although the efficacy was decreased with the passage of time after the injection of 54Mn, about 50% was still eliminated after 14 days. Repeated injection of this agent raised the efficacy, but the second or later injection was less effective than the first injection. Ca-DTPA eliminated the incorporated 54Mn by 57% for 100mg/kg and by 19% for 10mg/kg when it was injected after 3h. But after 6h or later, Ca-DTPA had little efficacy.
These results indicate that manganese chloride is very effective to eliminate the 54Mn from accidentally contaminated persons and the efficacy of Ca-DTPA is less than that of manganese chloride.
