Radiosensitivity of growing capillaries

• Published in: Journal of radiation research Vol. 25; no. 4; pp. 296 - 304
• Main Authors: Yamaura, H, Matsuzawa, T
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.01.1984
• Subjects: Animals; Capillaries - growth & development; Capillaries - radiation effects; Cobalt Radioisotopes; Dose-Response Relationship, Radiation; Male; Rats
• ISSN: 0449-3060; 1349-9157
• DOI: 10.1269/jrr.25.296

The radiosensitivity was studied on the capillaries growing in the rat transparent chambers. The proliferation of the capillaries was induced by the traumatic resection of the capillary bed in the transparent chambers and evaluated by the advancing speed of the vascularization borders invading the wounded regions. The transparent chambers were irradiated with Co-60 gamma-rays at various doses. The advancing speeds of the vascularization borders of the control, 50, 100, 200, 400, 600, 800, 1000, 1200, 2000 and 4000 rad groups were 0.18, 0.17, 0.15, 0.11, 0.10, 0.10, 0.08, 0.04, 0.05, 0.02 and 0.03 mm/day, respectively. These results showed two thresholds in the radiosensitivity of the growing capillaries: one at about 100 rad and the other at about 1000 rad. This double-thresholded radiosensitivity is discussed in relation with the possible endothelial stem cells.