The Preliminary Study Of Roxarsone On Angiogenesis

Roxarsone, an organoarsenic compand, is widely used in animal producing as a feed additive all over the world and there may be occurred the potential risk of cancer because of its angiogeniesis effect and the promotion to growth of human vascular endothelial cells reported recently. Few information is focused on the angiogenesis effect of roxarsone and no investigation was reported in the domestic now. This study was to primaryly explore the angiogenesis effects of roxarsone in vitro and in vivo using the models of chick chorioallantoic membrane angiogenesis assay and the rat aortic ring assay. It will accumulate the basic information of the special toxicity and be useful to evaluate the potential carcinogenic risk and the safety of the use in animal production as feed additives.The chick chorioallantoic membrane (CAM) angiogenesis assay was performed on the doses of roxarsone10.00,1.00,0.10μM and0.01μM,5.00ng/ml and10.00ng/ml VEGF as the positive control groups, the physiological saline as the negativethe control using7days of chicken embryo. The numbers of senior vessel and secondary vessel around the carrier1mm and1-5mm respectively and the ratio of new vessel area were calculated. Results showed that the numbers of senior and secondary vessels and the ratio of new vessels area in different roxarsone groups and the positive control of the VEGF was significantly increased (P<0.05) compared with that in saline control. These parameters were increased with the dose of roxarsone increase within0.01μM-1.00μM, showing a dose-response relationship, but that was decreased in10.00μM of roxarsone dose group and was equivalent to that of0.01μM. The maximun was in1.00μM of roxarsone group and have the similar results of the10.00ng/ml VEGF. In conclusion, roxarsone exhibited a clear angiogenesis on blood vessels of the chorioallantoic membrane in lower doses while the angiogenic promotion was reduced at higher doses of10.00μM.The rat aortic ring angiogenesis assay was processed as the same doses groups as in the CAM assay. The total number of sprouting vessels around the rings and the length of the longest vessel were as the parameters of evaluation at4day culturation, and the number of sprouting vessels in the regions was as the parameter of evaluation at6day culturation. Results showed that the total numbers of budding vessels in different doses of roxarsone and VEGF treatment were significantly increased compared with the negativethe control(P<0.05), which the parameter was increased with the dose of roxarsone increase at the range of0.01μM～1.00μM while the number of vessels was decreased at the dose of10.00μM roxarsone. The length of the longest vessel were significantly longer at different treatments of roxarsone compared with the negative control (P<0.05), but that was no significant difference in the VEGF groups (P>0.05). There was no significant difference within the different doses of0.10μM to10.00μM roxarsone. At6days culturation, the numbers of sprouting vessels in the regions were significantly increased at different treatements of roxarsone and the VEGF groups compared with the negativethe control group (P<0.05). The conclusion was that roxarsone appeared obvious angiogenesis on the rat aortic ring and the strongest effect of angiogenesis at1.00μM of roxarsone was similar with that of10.00ng/ml VEGF. Immunohistochemical of CD31to the sprouting vessels in rat aortic rings showed strongly positive.In summary, the angiogenesis effect was demonstrated by CAM assay and rat aortic rings assay in vitro and in vivo.