INTERSTITIAL FLUID PRESSURE, PERFUSION RATE AND OXYGEN-TENSION IN HUMAN-MELANOMA XENOGRAFTS

Interstitial fluid pressure (IFP) has been reported to be inversely co rrelated to rate of perfusion and oxygen tension (pO(2)) in experiment al tumours (Lee et al., 1992; Roh et al., 1998a). Studies of patients with squamous cell carcinoma of the uterine cervix have provided clini cal data consistent with the experimental data (Roh et al.; 1991b; Mil osevic et al., 1995). These observations have led to the hypothesis th at IFP might be a useful indicator of tumour oxygenation status. The p urpose of the work reported here was to examine in detail the general validity of this hypothesis. R-18 human melanoma xenografts grown intr adermally in Balb/c nu/nu mice were used as tumour model system. IFP a nd perfusion rate or IFP and pO(2) were measured in the same individua l tumours in two independent series of experiments. The wick-in-needle method was used to record IFP. Perfusion rate was studied by using th e Rb-86 uptake method. The KIMOC-6650 Eppendorf histograph was used to measure pO(2). IFP, perfusion rate and pO(2) differed considerably be tween individual tumours. However, there was no relationship between I FP and perfusion rate or IFP and pO(2), suggesting that the oxygenatio n status of tumours cannot be derived from measurements of IFP. Conseq uently, IFP is probably not a useful predictor of radiation resistance caused by hypoxia.