Study on the dosage of GMDTC for removing cadmium / 中国职业医学

ABSTRACT

OBJECTIVE: To explore different doses of sodium(s)-2-(dithiocarboxylato((2R,3R,4R,5R,6R)-2,3,4,5,6-pentahydroxyhexyl) amino)-4-(methylthio) butanoate(GMDTC) for removing cadmium. METHODS: Thirty-five male New Zealand rabbits were randomly divided into blank control group,GMDTC high dose control group,model control group,ethylene diamine tetraacetic acid(EDTA) control group and GMDTC low,medium and high dose groups,five rabbits in each group. The blank control group and GMDTC high dose control group were given 0. 90% normal saline solution intravenously; model control group,EDTA control group and GMDTC low,medium and high dose group were given 2 μmol/kg of cadmium chloride(CdCl_2) and 40 μmol/kg of β-mercaptoethanol mixed solution intravenously,5. 0mL/kg body weight(bw),once a day for five days. On the forty-one day of the experiment(the fist day of GMDTC treatment),the control group and the model control group were injected 0. 90% normal saline solution 250 mL via ear vein,the EDTA control group was given EDTA solution at the dose of 93. 5 mg/kg bw with 250 mL 0. 90% normal saline solution,also via ear vein; the GMDTC high dose control group,and the GMDTC low,medium and high dose groups were given 250 mL GMDTC solution at the concentration of 108.0,12.0,36.0 and 108. 0 mg/kg bw with 0. 90% normal saline by intravenous infusion,once a day,6 times a week for four consecutive weeks. The urine β_2-microglobulin(MG),renal cadmium,blood cadmium,and urinary cadmium before and after the treatment were detected. RESULTS: The body weight of New Zealand rabbits increased with the increasing feed time(P < 0. 01). The levels of β_2-MG before treatment increased in model control group,EDTA control group,GMDTC low,medium and high dose groups than that in the blank control group(P < 0. 01). The levels of renal cadmium after treatment in GMDTC medium and high dose groups decreased compared with those in the blank control group and EDTA control group respectively(P < 0. 05). The blood cadmium after treatment in EDTA control group,GMDTC low,medium and high dose groups were decreased compared with those before treatment in the same group respectively(P < 0. 05),meanwhile decreased than the blood cadmium after treatment in the model control group respectively(P < 0. 05). The blood cadmium after treatment had not a statistically significant difference among the EDTA control group,GMDTC medium and high dose groups(P < 0. 05). At all the time points(1,6,8,13,15,20,22 and 28 days after treatment),the urinary cadmium after treatment in EDTA control group and the three GMDTC dose groups increased compared to the model control group at the same time(P < 0. 05). The urinary cadmium after treatment increased with GMDTC dose increased at the other six time points,expect on 20 and 22 days after treatment(P < 0. 05). The blood cadmium removal rates after treatment were 70. 06%,74. 86% and 78. 05% and the renal cadmium removal rates were 14. 27%,27. 95% and 61. 24% in GMDTC low,medium and high dose groups,respectively. CONCLUSION: The intravenous infusion of GMDTC at the dose of 108. 0 mg/kg bw effectively removed cadmium in cadmium poisoning rabbit. This dose had no obvious toxic effect and was equivalent to human dose of 36. 0mg/kg bw which meets the requirement of new drug property.