Studies Of The Effect Of Lanthanum Chloride On The Enzymes, Lipid Peroxidation And Genetic Toxicity In Cyprinus Carpio Linnaeus

I n China,rare earth element (REEs) is widely used in agriculture,forestry,animal husbandry and aquaculture as microelement fertilizers or animal food,which brings about high environmental concern. To study the effect of REEs on natural water bodies and their influences on aquatic organisms is of major importance, especially in assessing potential risk of REEs. Cyprinus carpio Linn (carp)was chosen to be the experimental animal,the aim of this work was to study the effects of long-term(120d) exposure of rare element Lanthanum(La³⁺) on acute toxicity, physiology toxicity, and genetic toxicity of carp.1. Static-renewal acute test was used to study the acute toxicity of Lanthanum chloride (LaCl₃)on the carp. The results showed that the LD50 values of LaCl₃ to carp in 24h, 48h, 72h and 96h were respectively 13.20mg/L, 11.90 mg/L, 11.90 mg/L, 11.49 mg/L; the safe concentration value was 1.149mg/L.2.In the physiology toxicity experiment ,control group, four LaCl₃ treated groups (0.01mg/L,0.1mg/L,2mg/L,5mg/L)were set to treat the carp 120d.Then the activities of POD and SOD and contents of PLO were measured in brain ,muscle, liver and pancreas, kidney and gill of carp at 120d.Iso-enzymes of SOD and EST were analyzed by means of PAGE, too. The results showed that: (1) It was different to activities of SOD in different tissues of carp after a long-term treatment. In lower concentration (0.1 mg/L) treatment, the lanthanum could promote the activities of SOD in the brain, however, inhabit the activities of SOD in the liver and pancreas and kidney and gill. In higher concentration treatment , the activities of SOD were inhabited by lanthanum in liver and pancreas, muscle, gill, brain and kidney, it was significantly different (p<0.05 or p<0.01)in comparison with the control group in gill,liver and pancreas ,and muscle.(2)The detected activities of POD indicated that: the activities of POD in kidney, gill and muscle increased and it was significantly different (p<0.05 or p<0.01) in comparison with control group in lower concentration (0.01mg/L, 0.1mg/L) treatment. But it was not any significantly different (p>0.05) in higher concentration (2mg/L).At a range of experimental concentration, the activities of POD in brain showed a highly significant increase (p<0.05) in comparison with control group, but POD in liver and pancreas show a significant inhabit (p<0.05 or p<0.01).(3)The detected content of LPO indicated that:LaCl₃ produced a different effect on LPO in different issues of carp . Under induction of lanthanum, the content of LPO in liver and pancreas was raised, and gill reduced, but it did not show any significant difference (P>0.05) as compared to control group at a range of experimental concentration (0.01mg/L⁵mg/L).When carp exposed to lower concentration (0.01mg/L) of lanthanum, LPO was inhibited, however, to higher concentration, LPO was promoted in kidney, muscle and brain.(4) Iso-enzymes of EST and SOD showed that it has different results in brain, gill, liver and pancreas, kidney and muscle of carp. It appeared in the decreasing or increasing of enzyme activity and the disappearing or appearing of enzyme bands.3. The effects of LaCl₃ were studied on quantity of erythrocyte (RBC) and leucocyte (WBC) in the blood of carp. The results showed that LaCl₃ could increase the quantity of RBC at a range of experimental concentration (0.01mg/L⁵mg/L)and increase the quantity of WBC at lower concentration (0.01mg/L),and it was significantly difference (p<0.05 or p<0.01) in comparison with control group. But in the higher range of lanthanum concentration (0.1⁵mg/L), the quantity of WBC was reduced,and it was significantly difference (p<0.05) in comparison with control group at 5mg/L.4.The results of inducing micronucleus indicated that: La³⁺ could decrease the frequencies of micronuclei in the lower range of LaCl₃ concentration (0.01⁰.1mg/L) and induce it in the higher range of LaCl₃ concentration (2⁵mg/L), but it was not significantly different in comparison with control group. La³⁺ could decrease the frequencies of nuclear anomalies and total nuclear anomlies in the lower range of La³⁺ concentration (0.01²mg/L) and it is significantly different in comparison with control group in 0.1mg/L. However ,the frequencies of nuclear anomalies and total nuclear anomlies went up at 5mg/L.