[Intrinsic angiotensin II-generating system in human pancreatic cancer tissues]

To clarify whether an intrinsic angiotensin II-generating system exists in human advanced pancreatic cancer tissues, we measured angiotensin II concentration and angiotensin converting enzyme (ACE) activity in tissues of normal pancreas, pancreatic cancers, colon cancers and hepatocellular carcinomas. After the surgically resected specimens were homogenized, angiotensin II concentration and ACE activity in tissues were measured using the florisil method and Kasahara's method, respectively. Tissue angiotensin II levels in pancreatic cancers (n = 13) were significantly higher than those of normal pancreas (n = 7), colon cancers (n = 7), or hepatocellular carcinomas (n = 7). However, there was no significant difference in tissue ACE activity between them. This study provides in vivo evidence of ACE-independent angiotensin II-generating system in human pancreatic cancer tissues and suggests that this locally-formed angiotensin II influences the microenvironment of pancreatic cancer tissues in a paracrine fashion.