Effect of octreotide infusion on hepatic and tumour blood flow in two experimental models of liver metastases

Objective : To investigate the effects of octreotide infusion on hepatic and tumour blood flow in rats with experimentally induced liver tumours. Design : Blood flow was determined in tumour-bearing rats using a dual reference microsphere technique before and after intravenous infusion of octreotide. Methods : Tumours were induced in syngeneic rats by intraportal injection of K12-Tr and WB2054-M adenocarcinoma cells. Hepatic arterial and portal venous inflow, tumour blood flow and systemic arterial pressure were determined before and after octreotide infusion (0.05 μg/min). Results : In rats with K12-Tr tumours there was no change in tumour blood flow, hepatic arterial flow or portal venous inflow after octreotide infusion. In contrast, in rats with WB2054-M tumours, octreotide infusion resulted in a significant reduction in the blood flow to the hepatic tumour (from 0.37to 0.135 ml/min/g) but had no effect on hepatic artery or portal venous inflow. Conclusion : The reduction in blood flow to tumours derived from WB2054-M cells could, at least in part, explain the inhibitory effect of octreotide on the growth and development of these tumours. However, octreotide had no effect on blood flow to tumours derived from K12-Tr cells, suggesting that the analogue must inhibit tumour growth by other mechanisms.