The Role Of Adrenomedullin In The Pathogenesis Of Pheochromocytoma

Objective:Adrenomedullin (ADM) is a hypotensive peptide identified in the extrcacts of human pheochromocytoma tissue by Kitamura and his colleagues in 1993. It was found abundantly in many tissues . It was noted that ADM could play a role in regulating blood pressure as a circulating hormone in recent studies. But the effect of ADM on the pathogenesis of pheochromocytoma was not identified. Recently, a novel specific adrenomedullin receptor has been identified as a complex consisting of calcitonin receptor-like receptor(CRLR) and receptor activity modifying protein (RAMP)2 — RAMP2/CRLR. This receptor has previously been identified in normal adrenal tissues(including medulla and cortex), but there has been no report about whether RAMP2/CRLR mRNA is expressed in pheochromocytomas. The purpose of our research is to study the effect of ADM on the proliferation of pheochromocytoma cells, and to compare the expressions of ADM and its specific receptor in pheochromocytoma tissues with those in normal adrenal tissues .Methods:1. The human pheochromocytoma cells were collected with sequential enzyme digestion. Cell identification was performed with several methods. The growth of human pheochromocytoma cells and rat pheochromocytoma PC12 cells were determined with MTT method.2. The pheochromocytoma samples for RT-PCR were taken from 18 patients undergoing tumor resections from 2000 to 2003, while the normal adrenal tissues came from 8 cases of fresh accidental deaths. The mRNA expressions...