[Detoxification effects of two drugs in thallium -poisoned mice].

OBJECTIVE

To observe the thallium eliminating effect of prussian blue, pentetate zinc trisodium (Zn-DTPA), and their combined use in the treatment of acute thallium poisoning in mice.

METHODS

Thallium poisoned mice were reproduced by oral administration of 0.2 ml thallous nitrate (3 mg/ml). They were assigned randomly to four groups according to the random number table method, namely, model group, prussian blue group, Zn-DTPA group and the combination therapy group, with 10 mice in each group. Prussian blue was administered orally [4.52 g×kg(-1)×d(-1), total four times], and Zn-DTPA was injected intraperitoneally [500 mg×kg(-1)×d(-1), one time]4 hours after giving thallium. The dosage of both drugs in combination treatment was as the same as described above. After treatment for 5 days, all the animals were sacrificed. Brain, intestine, kidney and liver of 1 mouse from each group were collected for pathological examination to observe the necrosis. Thallium contents of blood, brain, urine and feces from the other mice were determined.

RESULTS

Pathological examination showed that the damage to intestine, kidney and liver was less obvious in treatment group compared with those of the model group. The effect was most obvious in the combination treatment group. However, brain damage was slightly improved. Thallium content in blood (mg/ml) of prussian blue group and the combination treatment group decreased obviously compared with the model group, and the decrease was more obvious in the combination treatment group (0.05 ± 0.01 vs. 0.18 ± 0.02). Thallium content in urine (mg/ml) and feces (mg/kg) was significantly increased after treatment, and the thallium elimination was most significant in the combined treatment group (urine: 11.34 ± 0.81 vs. 0.02 ± 0.01, feces: 13.11 ± 1.84 vs. 0.21 ± 0.07, both P < 0.01). Thallium content in brain was similar among all the groups.

CONCLUSIONS

The single and combined use of prussian blue and Zn-DTPA could reduce the damage in intestine, kidney and liver. Combined use of prussian blue and Zn-DTPA for acute thallium poisoning mice is more efficacious than single use of either drug.