Relationship Between Temperature and Blood Supply or Consumption of Oxygen and Glucose by Rat Mammary Carcinomas

Publisher Website
Google Scholar
Abstract
The relationship between tumor temperature and blood supply or O2 and glucose utilization was studied in 2 rat mammary carcinomas (Walker 256 and MTW9A) implanted in Sprague-Dawley and WistarlFurth rats. Tumors were warmer than the tissues receiving the transplant, and tumor temperature oscillated up to 2° C during a 24-hour period. Under constant ambient conditions, tumors cooled off while the host was anesthetized, and the rate of temperature depression varied with the anesthetic. When whole-body temperature was changed, increment or reduction of temperature in subcutaneous tumors preceded that of the subcutaneous tissue but trailed that of the abdominal cavity. Cooling of tumors that initially were at physiologic temperature almost consistently reduced the blood supply and O2 and glucose utilization. On the contrary, warming of tumors increased blood supply and O22 and glucose consumption only when the tumor's initial temperature was below normal. Warming of initially normothermic tumors failed to produce any consistent change in either the blood supply or O2 and glucose consumption. A doubling or tripling of blood flow was necessary to produce a 0.3–0.4° C increase In tumor temperature, and a large variability among different tumors occurred. No appreciable change in tumor temperature was produced by severe hyperglycemia or hypoglycemia or by extensive changes in O2 content In aortic blood. Drastic alterations in circulation and blood oxygenation were necessary to modify substantially tumor temperature, and the results were neither consistent nor conspicuous.