Plasma atrial natriuretic peptide and natriuretic peptide receptor gene expression in adipose tissue of normotensive and hypertensive obese patients

Paolo Dessi-Fulgheri, Riccardo Sarzani, Paola Tamburrini, Alessandra Moraca, Emma Espinosa, Giovanna Cola, Laura Giantomassi, Alessandro Rappelli

Research output: Contribution to journalArticlepeer-review

Abstract

Objective: Human and rat adipose tissue contain very high levels of natriuretic peptides clearance receptor messenger (m)RNA, and fasting inhibits its gene expression in adipose tissue. In this study we evaluated plasma atrial natriuretic peptide (ANP) and gene expression of biologically active type A natriuretic peptide receptor (NPr-A) and clearance natriuretic peptide receptor (NPr-C) in adipose tissue of obese hypertensive and obese normotensive patients. Design and methods: We studied 27 untreated obese hypertensives, 26 obese normotensives (body mass index ≤ 30 kg/m2), 24 non-obese essential hypertensives and 23 lean healthy subjects (body mass index ≤ 25 kg/m2). Blood samples were withdrawn for ANP, plasma renin activity and aldosterone radioimmunoassays. Subcutaneous peri-umbilical adipose tissue samples were obtained, by needle aspiration, in 13 obese hypertensives and in 12 obese normotensives and used for RNA extraction. Then, complementary synthesis and semiquantitative polymerase chain reaction (PCR) with primers complementary to sequences of different exons of the genes encoding for NPr-A, NPr-C and β-actin, were performed. 32P-labeled PCR products were separated by electrophoresis, blotted onto nylon membranes, and the exposed autoradiographic films were analysed by densitometry. NPr signals were normalized by the β-actin expression level. Results: Plasma ANP was lower in obese hypertensives than in obese normotensives (37.5 ± 7 versus 43.2 ± 6 pg/ml, P <0.05), but was higher in non-obese hypertensives than in non-obese normotensives. In contrast, plasma renin activity and aldosterone were higher in the obese hypertensives. Although NPr-A and NPr-C expression were not statistically different between the two obese groups, the NPr-A:NPr-C mRNA ratios were significantly lower in obese hypertensives (P <0.03). Conclusions: Our data suggest that in obese hypertensives compared to obese normotensives, the lower NPr-A:NPr-C ratio might determine decreased biological activity and/or an increased clearance of natriuretic peptide in adipose tissue, suggesting that the natriuretic peptide and its receptor system may be important in obesity-related hypertension where ANP levels are lower.

Original languageEnglish
Pages (from-to)1695-1699
Number of pages5
JournalJournal of Hypertension
Volume15
Issue number12 II
DOIs
Publication statusPublished - Dec 1997

Keywords

  • Adipose tissue
  • Atrial natriuretic peptide
  • Gene expression
  • Natriuretic peptide receptors
  • Obesity-related hypertension

ASJC Scopus subject areas

  • Internal Medicine
  • Endocrinology

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