Splanchnic blood flow changes in the presence of hepatic tumour: evidence of a humoral mediator.

Intrahepatic tumour is associated with alterations in splanchnic haemodynamics. To investigate the hypothesis that these are the result of a circulating vasoactive agent, rat small bowel segments were cross-perfused with arterial blood from groups (n = 12) of paired tumour-bearing (intrahepatic HSN sarcoma) and control rats. The vascular resistance of the segment was significantly greater during perfusion by tumour-bearing animals (91.6 mmHg ml-1 min, s.e. 21.5, vs 51.7 mmHg ml-1 min, s.e. 7.4, P < 0.05), suggesting that intrahepatic tumour may be associated with a circulating vasoactive agent. A similar mechanism may underlie changes in the hepatic perfusion index in patients with liver metastases.