CHARACTERIZATION OF THE VASCULATURE WITHIN A MURINE ADENOCARCINOMA GROWING IN DIFFERENT SITES TO EVALUATE THE POTENTIAL OF VASCULAR THERAPIES

Numerous vase-active agents can affect vasculature in experimental sol id tumours growing subcutaneously (s.c.), but these models are unlikel y to reflect the vasculature of metastatic disease in man. The present study describes a murine orthotopic colon tumour which metastasises t o the liver. Morphology and vascular pattern of caecal tumours is simi lar to s.c. tumours. Vascular occlusion caused by intravenous (i.v.) n oradrenaline (NA) (160 mu gkg(-1)) and hydralazine (HDZ) (10 mgkg(-1)) was 32% and 59% respectively for the caecal tumours compared with 35% and 78% for s.c. tumours. Significant morphological differences were seen between liver metastases and systemic deposits produced by i.v. i noculation of tumour cells. Liver metastases following orthotopic tran splantation contained functional vasculature but no significant occlus ion was seen with NA or HDZ. The vascular development and morphologica l appearance of secondary disease resulting from orthotopic implantati on suggests that this would be a useful model for the study of agents that act either by vascular or anti-angiogenic mechanism.