Blood flow influences vascular growth during tumor angiogenesis

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 12670912
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Radiation science
• Research Institution: Kansai Medical University
• Principal Investigator: AKAGI Kiyoshi Kansai Medical University Faculty of Medicine Assistant Professor, 医学部, 講師 (30098115)
• Project Period (FY): 2000 – 2001
• Keywords: experimental tumor / Transparent chamber / neovascularization

Research Abstract

We observed growing tumor vessels in vivo to study the relationship between blood flow and vascular enlargement. Mammary adenocarcinoma was implanted into Fisher-344 rat with dorsal shin-fold transparent chambers. Vascular growth was observed and recorded on videotape through a microscope for 6h. Vascular networks were photographed and traced every 30min. To identify changes over time. Tumor sections were stained with Masson's trichrome and anti-Factor-8 related antigen. Tumor growth was rapid enough for differences to be seen each hour. Vessels with a high blood flow showed an increase in diameter within a few hours and new branches formed from these vessels. In contrast, vessels without an increase in blood flow showed no change in diameter. Vessels within the interstitium surrounding the tumor were lined by endothelium that was positive for anti-8 related antigen staining. Vessels in the tumor had extremely rare endothelial cells detectable by masson's trichrome or anti-8 related antigen staining. In conclusion, increased blood flow may cause vascular enlargement and some primitive vessels seem to lack endothelium.