EFFECTS OF OCTREOTIDE ON LIVER-REGENERATION AND TUMOR-GROWTH IN THE REGENERATING LIVER

The ability of the liver to regenerate following resection is remarkab le. However, there is evidence to suggest that tumour growth within th e regenerating liver is significantly increased. As octreotide (a synt hetic analogue of somatostatin) inhibits the growth and development of hepatic tumour in rats, we have investigated its effects on liver reg eneration, liver blood flow, hepatic reticuloendothelial system activi ty and tumour growth in the rat following partial hepatectomy (PH). Oc treotide significantly inhibited liver regeneration in the rat 1 and 2 weeks following PH when compared with controls (regeneration index: 1 .0 and 1.14 cf: 1.14 and 1.4, respectively). There was no significant difference in hepatic arterial or portal venous blood flow following P H in control or octreotide-treated rats. However, portal pressure was significantly reduced in octreotide-treated rats. Hepatic reticuloendo thelial system activity was significantly increased in octreotide-trea ted rats compared with control animals 1 and 2 weeks after hepatectomy (uptake of radiolabelled technetium-99m albumin colloid: 2.2 and 3.9 cf. 1 6 and 1.9). The growth of both HSN (fibrosarcoma) and K12-Tr (co lonic adenocarcinoma) cells in the regenerating liver was significantl y decreased by octreotide treatment compared with controls (median per centage hepatic replacement: HSN control 71.3%, Octreotide 8.4%, K12-T r Control 38.3%, Octreotide 4.5%). The results of the present study de monstrate that octreotide inhibits both liver regeneration and tumour growth following PH, possibly via a similar mechanism.