title: Expression of type 1 angiotensin II receptors in human aldosteronomas.
abstract: Type 1 angiotensin II (AII) receptors (AT1 receptors), besides stimulation of aldosterone secretion, seem to transduce the growth factor-like activity of AII on glomerulosa cells. Although a local renin-angiotensin system and AII synthesis have been found in human adrenals and aldosteronomas, it is unclear whether aldosteronomas express AT1 receptors. Utilizing polymerase chain reaction (PCR) and reverse transcription-PCR (RT-PCR) with primers complementary to both genomic and cDNA sequences of human AT1 receptor, we have amplified and cloned a 734 bp fragment of the AT1 coding region. This DNA, after cloning and sequencing, was used for Northern analysis. Total RNA was extracted from 5 non-tumorous adrenals and 5 aldosteronomas. AT1 mRNA (approximately 2.4 kb) was expressed in all the aldosteronomas tested. Densitometric analysis of AT1 signals, corrected by beta actin expression, when compared to non-tumorous adrenals, did not show significant differences. AT1 receptor density and affinity in cell membrane obtained from 9 non-tumorous adrenal cortex and 8 aldosteronomas were also studied. 125I-AII was used as ligand and Dup 753 as AT1 antagonist: AT1 receptor density and affinity were not significantly different in aldosteronomas vs non-tumorous adrenal cortex. In conclusion, the expression of AT1 gene and the formation of an apparently normal receptor suggest that AT1 receptor should have a role in aldosteronoma cell biology.
authors.affiliation: Institute of Clinical Medicine, University of Ancona, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Sarzani
authors.forename: G
authors.initials: G
authors.lastname: Opocher
authors.forename: P
authors.initials: P
authors.lastname: Dessì-Fulgheri
authors.forename: V
authors.initials: V
authors.lastname: Paci
authors.forename: G
authors.initials: G
authors.lastname: Cola
authors.forename: S
authors.initials: S
authors.lastname: Rocco
authors.forename: B
authors.initials: B
authors.lastname: Vianello
authors.forename: F
authors.initials: F
authors.lastname: Mantero
authors.forename: A
authors.initials: A
authors.lastname: Rappelli
mesh_terms: D000306:Adrenal Cortex Neoplasms / Q000378:metabolism*; D000450:Aldosterone / Q000378:metabolism*; D001483:Base Sequence; D006801:Humans; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000096:biosynthesis*; D011945:Receptors, Angiotensin / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D011945:Receptors, Angiotensin; D000450:Aldosterone