Expression Of Angiotensin â…¡ Receptors In Aldosterone-producing Adenoma

Objective: The study aimed to investigate the expressions of angiotensin II type 1 receptor (AT₁R) and type 2 receptor (AT₂R) in aldosterone-producing adenoma (APA).Methods: 50 APAs specimans including adenomas and para-adenomas and 12 normal adrenal cortical tissues were collected from 2007 to 2009 in Tongji hospital. The mRNA expressions of AT₁R and AT₂R in all specimens were detected using RT-PCR. Furthermore, the protein expressions of AT₁R and AT₂R were measured using immunohistochemistry.Results: The relativle expression levels of AT₁R in APAs, para-adenomas and normal adrenal cortical tissues is 0.62±0.12, 0.49±0.14 and 0.54±0.11, respectivly.Between these 3 kinds of tissues, there was no significant difference in AT₁R mRNA expressions (p>0.05), and for the alternativly spliced AT₁R mRNA, the relative expression levels of E15, E125/E135 and E1235 mRNA also have no differences. The mRNA expression of AT₂R, however, was significantly lower in APAs than in normal adrenal cortical tissues (APAs vs. control: 0.12±0.01 vs. 0.26±0.06, p<0.05). A similar trendation was further observed in the protein expressions of AT₁R and AT₂R in APAs, para-adenomas and normal adrenal cortical tissues.Conclusions: There was no significant difference in total and alternatively spliced mRNA expression of AT₁R between APAs, para-adenomas and normal adrenal cortical tissues. It may be speculated that the AT₁R has no contribution to the APAs pathogenesis. The down-regulated expression of AT₂R may be associated with the pathogenesis of the adrenocortical adenoma.