Physiological effects of hyperthermia: response of capillary blood flow and structure to local tumor heating.
Specific capillary blood flow and small-vessel pathology in animal tumors (rhabdomyosarcoma BA-1112) of WAG/Rij rats were examined following local tumor heating to 40-44.5 degrees C. Blood flow in tumors heated to 40-41 degrees C for 40 minutes was reduced initially by about 50%, but returned to near preheating values within 72 hours, consistent with the histopathological observations indicating small-vessel dilation and temporary congestion. The application of hyperthermia greater than 43 degrees C (for 40 minutes) resulted in the virtual elimination of capillary blood flow, consistent with pathological findings of widespread vessel rupture and hemorrhage in this temperature range.
D000818:Animals; D002196:Capillaries; D006358:Hot Temperature; D008833:Microcirculation; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000098:blood supply / Q000473:pathology; D051381:Rats; D012208:Rhabdomyosarcoma / Q000098:blood supply* / Q000473:pathology; D014184:Transplantation, Homologous