Abstract of the 68th Meeting (Spring Meeting) 6–9 March 1990, Heidelberg

Laser Doppler flux and tissue oxygenation of experimental tumours upon local hyperthermia and/or hyperglycaemia

Laser Doppler fluxmetry and oxygen partial pressure (pO2) histography have been applied to investigate the acute effects of hyperthermia (HT) and/or hyperglycaemia (HG) on microcirculatory function and tissue oxygenation of subcutaneous rat tumours growing on the dorsum of the hind foot. The experiments were performed to test whether, and to what extent, the two adjunct treatment modalities applied alone or in combination can modify these therapeutically relevant parameters. Local HT was performed in a saline bath (44 degrees C) for 2 h; HG was induced by i.v. infusion of 40% glucose solution for 2.5 h (blood glucose levels: 35-40 mM during heating). Laser Doppler flux (LDF) in superficial …

Tumor blood flow: The principal modulator of oxidative and glycolytic metabolism, and of the metabolic micromilieu of human tumor xenograftsin vivo

We have investigated therapeutically relevant pathophysiological parameters of human breast and lung cancer xenografts in nude rats. All lung cancers and one breast cancer exhibited rapid growth and high blood flow values paralleled by high metabolic rates. The tissue of these tumors was well oxygenated up to very advanced growth stages. Xenografts from other breast cancer cell lines grew much more slowly, were poorly perfused, and exhibited low metabolic rates. Here, tumor hypoxia and tissue acidosis were evident. These results indicate that significant differences in the metabolic micromilieu can be detected in human tumors; these are due to varying perfusion rates and may be partly respo…

Acute changes of systemic parameters in tumour-bearing rats, and of tumour glucose, lactate, and ATP levels upon local hyperthermia and/or hyperglycaemia

Arterial blood pressure and relevant parameters of the arterial blood (O2 and CO2 tensions, pH, haematocrit, serum electrolytes and osmolality) were determined in tumour-bearing rats upon local hyperthermia (HT) and/or hyperglycaemia (HG). Tumour heating was performed in a saline bath (44 degrees C) for 120 min; hyperglycaemia was induced by i.v. infusion of 40% glucose solution for 150 min [blood glucose levels: 35-40 mM during heating; total amount of glucose: 1.19 g/100 g body wt.; infusion rates: 0.31 ml (100 g body wt.)-1 min-1 for 2 min, 0.02 ml (100 g body wt.)-1 min-1 for 88 min, and 0.01 ml (100 g body wt.)-1 min-1 for 60 min]. Immediately after treatment, glucose, lactate and ATP …