Studies On Antiangiogenesis Of MD Tumor Induced By Arsenic Trioxide

Marek's disease(MD) is a malig chicken's tumor disease induced by herpesvirus Marek'sdisease virus(MDV), it can induce immunity inhibition of the host, and the chickens finally diebecause of the damage of the organ function. Though the effective vaccines had been developed, butthere were many reasons such as defult of immunization, the immuned poultry still infected of MD.This brought great difficulies to control MD, and influenced the healthy development of poultryindustry seriously. Meanwhile, as the first successful case that prevented effectively by vaccine, MDwas payed great attention on the study of the occuration, development and immunization of virustumor disease by medicine fields. Antiangiogenesis is a new way to treat with tumor. It is payedmore and more attention by the scholars because of it's superiority. But there are still not correlativestudies on the angiogenesis of MD and the effective of arsenic trioxide on angiogenesis of MD. Themechanism of antiangiogenesis of MD induced by arsenic trioxide was studied in this article byusing of YiSha chicken. The experiment route was that duplicating the MD model artificially, anddetecting by the expression degree of mRNA of VEGF,KDR,bFGF and iNOS in the tumor., theapoptosis of tumor vascular endothelial cell (VEC) and NO-NOS active system. by intraperitionealinjection As₂O₃ And this provided theoretical reliances for comparative medicine and clinicalmedicine. The results suggested that:1 Firstly measuring the LD₅₀ of chickens by intraperitioneal injection As₂O₃ and the outcome was8.877mg per kg weight, and cumulative effect was low-grade. This provided reliance for clinicaltreatment.2. Observed under the clinical dissection and histology, the duplicating of MD model was provedto be successful.3. The detection of TUNEL suggest that As₂O₃ could promote the apoptosis of tumor vascularendothelial cell to inhibit the growth of tumor.4. When the chickens infected with MD virus, the contents of NO and the activity of NOS were allraised, and the expression degree of the iNOS mRNA was raised apparently when tested byRT-PCR. When injected with arsenic, the contect of NO,the activity of NOS and the expression ofiNOS mRNA were all had the tendency of decline. This suggested that the tumor organ of MD couldinduce secreting plenty of iNOS and regulating the synthesis of NO. And As₂O₃ could inhibit thetumor secreting iNOS, reduce the synthesis of NO, inhibit the division and hyperplasia ofendotheliocyte and decline the angiogenesis.5. Testing the expression degree of VEGF and KDR mRNA in tumor organ by RT-PCR, the result showed that the expression degree raised when the chickens infected with MDV. By intraperitionealinjection As₂O₃, the expression degree of VEGF and KDR would get down. This proved As₂O₃ couldreduce the secretory action of VEGF, inhibit the angiogenesis of tumer, by getting down the highexpression of VEGF and KDR mRNA.6. Using RT-PCR to test the expression degree of bFGF mRNA in tumor organ. The resultsshowed that the expression degree of bFGF mRNA getting high when the chickens infected withMDV, and when injected with As₂O₃, the high expression of bFGF mRNA could be got down. Thissuggested that the continuance action of As₂O₃ could reduce the high expression of bFGF mRNAapparently, reduce the autocrine and paracrine of angiogenesis regulatory factor, and reduce theangiogenesis of tumor to inhibit the growth of tumor thereby.