0000000000359577
AUTHOR
Britton Chance
Tissue gradients of energy metabolites mirror oxygen tension gradients in a rat mammary carcinoma model
Abstract Purpose: It has been shown that oxygen gradients exist in R3230AC tumors grown in window chambers. The fascial surface is better oxygenated than the tumor surface. The purpose of the present study was to determine whether gradients exist for energy metabolites and other end points related to oxygen transport. Methods and Materials: Imaging bioluminescence was used to measure ATP, glucose, and lactate in cryosections of R3230AC tumors. Mean vessel density and hypoxic tissue fraction were assessed using immunohistochemistry. Tumor redox ratio was assessed by redox ratio scanning. Results: Lactate content and hypoxic fraction increased, whereas ATP, glucose, redox ratio, and vessel de…
Microcirculatory Function, Tissue Oxygenation, Microregional Redox Status and ATP Distribution in Tumors Upon Localized Infrared-A-Hyperthermia at 42°C
Since local hyperthermia (HT) affects microenvironmental parameters, the aim of the study was to analyze the impact of 42°C-HT on microcirculatory function, tumor pO2, microregional redox status and ATP distribution in experimental rat tumors. Subcutaneously growing DS-sarcomas were treated with localized HT using infrared-A radiation resulting in a mean tumor temperature of 42°C. The relative red blood cell (RBC) flux in the tumor was assessed using the laser Doppler technique and the mean tumor pO2 measured continuously using O2-sensitive catheter electrodes. In a second series of experiments, the microregional distribution of the mitochondrial redox status and ATP concentration was measu…