Studies Of Mutagenesis Induced By Lead And/or Ethanol And Antagonistic Effect Of Selenium On Male Mice

Objective:Lead is one of the most common chemical toxicants. Cell mutation can be induced by lead. Ethanol also can induce damage on the health of people. They existed extensive in environment. Many people exposure to lead and ethanol with high frequency. But there is only a few reports about combined effect of lead and ethanol on male mutation. Selenium is an essential microelement, a major component of glutathione peroxidase (GSHPx) and it can provide protective effect to the hazards of chemicals. So, the present study was undertaken to clarify whether lead and ethanol have combined effect on male mutation and whether selenium have antagonistic effect on male mutation induced by lead and ethanol through medulla micronucleus, medulla chromosome aberration and primary spermtocyte chromosome aberration. The aim is to provide scientific basis in order to protect people from genetic toxicity of lead and ethanol.Methods: 112 healthy male mice were divided into 14 groups randomly, eight mice every group. Treatment includes negative, positive control groups and A~K treatment groups.A~D is lead or ethanol treatment, which represents low-lead (LL), high-lead(HL), low-ethanol(LE), high-ethanol(HE) groups; E~H is co-administration groups (LL+LE, LL+HE, HL+LE, HL+HE groups); I~L is selenium pre-treatment groups(selenium+co-administration groups). Lead acetate and ethanol were given at the dosage of 15 , 30mg/kg and 1000 , 2000 mg/kg body weight respectively through oral exposure for 5 days/week, one time/day for three weeks. Selenium was given at the dosage of 1mg/kg body weight through ingestion paunch (ip) one hour ahead of oral exposure everyday. Distilled water was given at the same dosage in negative group. Cyclophosphamide (CP) was given at the dosage of 40mg/kg body weight through ip for 5days in positive group. The 25th day after first exposure the half animal of each group were taken breastbone marrow out and micronucleus were observed; the other half were taken thighbone marrow and testis out to analysis marrow cell chromosome aberration and primary spermatocyte chromosome aberration after inject colchicines (4μg/g ) 4 hours.Results: 1.Effects of lead and ethanol on micronucleus: micronucleus rate in HL and LL treatment group were significant higher than that of negative control (P<0.01), which indicated that lead acetate have mutagenesis on marrow cell micronucleus. Significant increasing was observed on rate of micronucleus in LE and HE groupscompared with negative control (P<0.05 or P<0.01). Micronucleus rate of HE group were significant higher than that of LE group(P<0.05). Significant increasing was observed in co-administration groups compared with negative control group. Factorial analysis showed that lead and ethanol have interaction effect on the rate of micronucleus. Co-administration with lead and ethanol had an increasing-toxicity effect. Analysis of variance showed that rate of micronucleus of HL+HE group increased compared with lead or ethanol alone groups (P<0.01). Significant differences were observed between HL+LE group compared with LL and LE group (P<0.01). After treatment with selenium the rate of micronucleus of selenium groups was greatly decreased compared with corresponding co-administration groups. No difference was observed between selenium+ LL+LE group and negative control groups, which indicate that selenium had an antagonistic effect on micronucleus induced by lead and ethanol of low dosage. 2. Effects on lead and ethanol on marrow cell chromosome: Chromosome aberration of marrow cell was observed after exposure to lead. Chromosome aberration rate of HL group was increased significantly compared with negative control group (P<0.01) or with LL group (P<0.01). Chromosome aberration rate of HE group was increased significantly compared with negative control group (P<0.01).After exposure to lead and ethanol co-administration the rate of chromosome aberration significant increased in LL+HE, HL+LE, HL+HE groups compared with negative control group...