STABLE BIOENERGETIC STATUS DESPITE SUBSTANTIAL CHANGES IN BLOOD-FLOW AND TISSUE OXYGENATION IN A RAT-TUMOR

Experiments on s.c. rat tumours (DS sarcoma) were performed to determi ne whether chronic or acute changes in tumour perfusion necessarily le ad to changes in tissue oxygenation and bioenergetic status since, as a rule, blood flow is thought to be the ultimate determinant of the tu mour bioenergetic status. Based on this study, there is clear experime ntal evidence that growth-related or acute (following i.v. administrat ion of tumournecrosis factor ct) decreases in tumour blood flow are ac companied by parallel alterations in tissue oxygenation. In contrast, tumour energy status remains stable as long as flow values do not fall below 0.4-0.5 mi g(-1) min(-1), and provided that glucose as the main substrate can be recruited from the enlarged interstitial compartment . Perfusion rate seems to play a paramount role in determining energy status only in low-flow tumours or low-flow tissue areas.