Studies Of Toxicity Of Aroclor 1254 On Early Mouse Embryo Development In Vitro

The experiment to begin with culturing the 2-cell mouse embryos, and the different dose of Aroclor 1254 were added into the embryos culture medium of the mouse in vitro. Approached the effects of Aroclor 1254 on the development of the early mouse embryos in vitro, and analyzed the toxicity mechanism of Aroclor 1254 on early mouse embryos.1. To sieve culture system fitting Kun-bai mouse embryo ectogenesis 6, 7, 8, 9 and 10 weeks old mice were selected and superovulated. Two-cell mouse embryos were taken out and put into CZB culture medium containing 10 % (v/v) FBS, BS and NBS, respectively, instead of bovine serum albumin (BSA). 5.56 mmol/L glucose concentrated solution was added into the culture medium containing 10 % NBS after 0, 8, 16 and 24 hrespectively The results indicated that 6, 7, 8, 9 and 10 weeks old each mouse could obtain 16.8, 37.3, 47.9, 44 and 41 embryos on average, respectively.The employed embryos that were suitable to culture continued in 8 weeks (90.9 %) and 9 weeks (89.9 %) were higher significantly than those of 6 and 7 weeks(p<0.05).The developmental rate (83.3 %) and hatching rate (71.4 %) of embryos cultured in the CZB culture medium containing 10 % NBS were significantly higher than that of BS (30.6 %, 55.4 %) and FBS (18.8 %, 43.0 %) (p<0.01); After 0, 8, 16, 24 h, the culture embryos were changed into the CZB culture fluid with 5.56 mmol/L glucose and the embryos morula rate were 0, 58.7%, 75.9 %, 90.5 % and 78.8 %, the blastula developmental rate were 0, 30.4 %, 53.1 %, 84.6 % and 41.7%, respectively.The conclusion was that the mice of 8 weeks and 9 weeks'old had the best superovulation effect, and FBS, BS could not instead of BSA, but NBS could, and after cultured in CZB culture medium 16 h, the embryos, which changed into the containing glucose CZB culture medium, had the highest blastula developmental rate (84.6%).2. The aim of this study was to investigate the effect of Aroclor 1254 on 2-cell mouse embryos development in vitro.The mouse embryos at 2-cell stage were exposed to Aroclor 1254 of 0.05, 0.25, 1.25and 6.25μg/mL, comparing to solvent control group(containing ethanol) and blank control group.The result indicated that Aroclor 1254 with 0.05μg/mL could effect embryo-hatching proportion(55.7 %)of the 2-cell, which had significant difference compared with the control group of dissolvent (66.7 %) (p<0.05); The blastocyst development rate(72.5 %) and hatching rate(23.2 %) at 0.25μg/mL of Aroclor 1254 have significant difference with the solvent control group (84.2 %, 66.7 %) (p<0.01); The embryos development rate from 2-cell to 8-cell (32.1 %)with the concentration of 6.25μg/mL Aroclor 1254 is notably lower than that of the control group. The embryos development rate from 2-cell to 4-cell and to 8-cell with 6.25μg/mL Aroclor is significant lower than that of the control group(p<0.01).The conclusion was that Aroclor 1254 effect the mouse embryos development according to the dose-toxicity in vitro; As the dose of Aroclor 1254 increases, the toxical effect to mouse embryos development would become earlier and act more fiercely.The younger the embryos were, the more sensitive to Aroclor 1254 were.3. The objective of this study was to investigate the effect of Aroclor 1254 on 8-cell mouse embryos development in vitro.The mouse embryos at 8-cell stage were exposed to Aroclor 1254 of 0.05, 0.25, 1.25μg/mL and 6.25μg/mL, comparing to solvent control group(containing ethanol) and blank control group. The result indicated that 0.05μg/mL Aroclor 1254 had no significant impact on the development of 8-cell embryos. 0.25μg/mL Aroclor 1254 could effect the incubation (64.7 %) of the 8-cell embryos, which was striking difference from the solvent control group(p<0.05). The blastocyst development rate(68.6 %) and hatching rate(25.5%) of the 8-cell embryos with 0.25μg/mL Aroclor 1254 were lower predominantly than the solvent control group(92.4 %, 75.7 %)(p<0.01). The 8-cell embryos with 6.25μg/mL Aroclor 1254 could not develop. The conclusion is that Aroclor 1254 effects the mouse embryo development according to the dose-toxicity in vitro.