Background
To investigate impacts of sodium arsenic (NaAsO2) on embryonic cardiac development in rats and evaluate the protective role of folate in NaAsO2 exposure rats.
Conclusion
NaAsO2 induce embryonic cardiac defection and folate supplement alleviate this impairment through modulation of the Nkx2.5, GATA4 and TBX5 gene expression.
Methods
We divided 90 female rats randomly into 9 groups. Group A was the control; group B-F were the animals fed with NaAsO2 in a series of increased doses, corresponding to 9.4 mg/L, 18.8 mg/L, 37.5 mg/L, 75 mg/L and 150 mg/L, respectively; group G-I were fed with 75 mg/L of NaAsO2, in addition of folate with doses of 0.53 mg/kg, 5.3 mg/kg, and 10.6 mg/kg, respectively. Their fetus' general development and cardiovascular systems were examined. Nkx2.5, GATA4, TBX5 gene and protein expression were measured.
Results
Relatively to group A, arsenic treated group C-F rats generated significantly lower weight of fetus and placenta (P<0.05), whereas the folate-treated groups H and I were significantly heavier than the arsenic-treated group E (P<0.05). We observed that incidences of cardiac malformations were significantly greater in arsenic-treated group E and F than group A (P<0.05). We found that the Nkx2.5 and GATA4 protein expression in the fetal hearts were downregulated in group B-F compared to group A. But the expression of them was significantly upregulated in group H-I relatively to group E (P<0.05). Moreover, the TBX5 gene expression was increased in both group D-F and G-I when they were compared to group A or group E, respectively (P<0.05).