Effect Of Excess Addition Of Chromium Picolinate On DNA Of Piglet Cell

Two experiments were conducted in this study to investigate effects of basic diet added excess chromium picolinate on DNA of piglet cell.In experiment 1, piglet hepatocytes obtained at 7days were cultured adherently. When the number of adherent hepatocytes is above 80 percent, then cultured them in the different culture medium including different concentration of chromium plicolinate([Cr(pic)3]). The hepatocytes were randomly divided into 4 groups with 4 repeats per group, and treated for 48h with [Cr(pic)3] at final concentration of 0, 8, 200 or 400μM. After 48 hours, cells were harvested to measure the growth density. The result showed that the number of hepatocytes decreased with the increase of the supplement of [Cr(pic)3]. When the concentration of chromium plicolinate was 400μmol/L, the density of hepatocyte was less thanⅡ,Ⅲgroup (P<0.05). But there was no significance betweenⅣgroup and control group(P>0.05). At the same time, there was no significance among 0,8μM,200μM [Cr(pic)3] group. About the comet figure, no significance was discerned in the comet tail DNA% concentration when the 8μM,200μM,400μM [Cr(pic)3] group were compared with the control group. The comet length ofⅡ,Ⅲgroup were lower than the control group(P<0.05). The difference of comet length between 400μM group and control group was not significant. In terms of comet tail length, the ratio of comet tail length and comet length, comet tail moment, comet Oliver tail moment and the percentage of DNA-Protein crosslink, no significant was detected between all [Cr(pic)3] groups and control group(P>0.05).In experiment 2, thirty pigs weighting (30±1)kg (Yorkshire×Landrance×Duroc) were divided into five groups with six replications per group,Ⅰ, basal diet (B);Ⅱ,B+200μg/(kg.diet) [Cr(pic)3];Ⅲ,B+800μg/(kg.diet)[Cr(pic)3];Ⅳ,B+1600μg/(kg.diet) [Cr(pic)3];Ⅴ, B+3200μg/ (kg.diet)[Cr(pic)3]. The 8-OHdG content at the 35th day of trail showed that there was no significance between all [Cr(pic)3] group and the control group (P>0.05). At the same time, there was no significance among all [Cr(pic)3] groups. At the 80th day, the result showed that the 8-OHdG content of all [Cr(pic)3] lower than the control group as a whole(P>0.05). And the content of 8-OHdG betweenⅤandⅠgroup is rather close. Furthermore, we concluded that the content of 8-OHdG ascended slowly with the increase of the [Cr(pic)3] concentration in the diet. But the difference was not significant (P>0.05). With regard to DNA alkaline unwinding(DAU) F value of liver and kidney, they experienced a descending trend with the increase of [Cr(pic)3] concentration. But no significance was descended (P>0.05) when all [Cr(pic)3] treats were compared with the control group.In summary, (1) in vivo research showed that [Cr(pic)3] at the concentration of lower than 400μmol/(L.medium) had no effect on DNA integrality of piglet hepatocytes; (2) in vitro research showed that [Cr(pic)3] at the concentration of lower than 3200μg/(kg.diet) had no damage effect on DNA of liver and kidney of piglet; (3) [Cr(pic)3] at the low concentration had protective effects and anti-oxidative effects on cells and DNA structure of piglet hepatocytes and liver cells.