title: Tumor microvasculature following fractionated x irradiation.
abstract: The microvasculature of C3H/Bi mouse mammary carcinomas 8 mm in average diameter was evaluated using morphometric methods following six consecutive daily exposures of 500 R of x radiation. Tumor volume did not change significantly during the intervals between treatments. Tumors began to grow again 72 hours after the sixth 550-R fraction, with mean vessel length and surface area reaching maximum values and vessel diameters and volumes becoming minimal at this time. These changes were attributed to improved colloidal-carbon filling of previously existing nonfunctional vessles. When anatomically derived estimates of vascular dimensions were related to a metabolically useful blood supply, improved capability for exchange of essential nutrients occurred 72 hours after the sixth 500-R fraction.
mesh_terms: D000818:Animals; D002244:Carbon; D003102:Colloids; D003287:Contrast Media; D008325:Mammary Neoplasms, Experimental / Q000473:pathology / Q000532:radiotherapy*; D051379:Mice; D008815:Mice, Inbred Strains; D008833:Microcirculation / Q000473:pathology / Q000528:radiation effects*; D009368:Neoplasm Transplantation; D011830:Radiation Effects; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy; D013848:Thigh / Q000601:surgery
chemical_list: D003102:Colloids; D003287:Contrast Media; D002244:Carbon