Experimental Study Of The Effect Of CO₂ Pneumoperitoneum On Colon Carcinoma Growth And Metastasis And The Interventional Effect By Intraperitoneal Chemotherapy

Objective: To establish an orthotopic transplantation model of human colonic tumor in nude mice and study the effect of CO₂ pneumoperitoneum on colon carcinoma growth and metastasis, then intraperitoneal chemotherapy was performed to intervene it. To investigate the influence and significance of CO₂ pneumoperitoneum and intraperitoneal chemotherapy on hypoxia-inducible factor-1α(HIF-1α) and vascular endothelial growth factor (VEGF) expression in colon carcinoma.Methods: The cell LoVo in log phase of human colon adenocarcinoma was inoculated subcutaneously into nude mice to develop the implantation tumor. Tumor tissue was then collected and orthotopically implanted to the colon wall of mice with ZT glue to set up a model of colon carcinoma. 10 days later, the mice were randomized into 3 experimental groups: the anesthesia control group(A, n=10); the CO₂ pneumoperitoneum group (B, n=18) and the CO₂ pneumoperitoneum with intraperitoneal chemotherapy group (C, n=18). Pneumoperitoneum was established in group B and C with an intra-abdominal pressure of 10mmHg for an hour. After the laparoscopic operation, the mice of group C were taken an intraperitoneal chemotherapy with 5-F1uorouracil and calcium folinate from the first postoperative day to the 5th day. 6 weeks later after the second operation, the mice were sacrificed and observed its weights, tumor volumes and port-site metastases. Except for one mouse died , 45 samples of colon carcinoma tissues were examined for HIF-1αprotein and VEGF protein expression by EnVision immunohistochemical method.Results: One nude mouse died of laparoscopic operation, the rest all formed in situ masses of colon carcinoma and some of them had metastases. The weights of the experimental mice had no significantly difference between the groups, while the difference of the volume of in situ tumors and port-site metastases were significant(P<0.05 and P<0.01). The protein expression levels of HIF-1αand VEGF in the tumor tissues of group B were higher than those in group A and C respectively (P<0.05 and P<0.05), while the expression levels between group A and C had no significantly difference (P>...