title: Endothelin-1 and endothelin a receptor immunoreactivity is increased in patients with diabetic nephropathy.
abstract: BACKGROUND
  Endothelin-1 (ET-1) is associated with progression of renal disease, acting as a vasoconstrictor and growth factor for mesangial cells. ET-1 and endothelin A receptor (ET-RA) might have a role in the development of diabetic nephropathy (DN). The aims of this study were to determine ET-1 and ET-RA expressions in patients with DN and to correlate these expressions with renal function and proteinuria.
  
  
  METHODS
  This is a cross-sectional study comprising 13 patients with type 2 diabetes mellitus and DN, 10 patients with proteinuric IgA nephropathy, and 13 samples of normal kidney from tumor nephrectomies. Demographic and selected data were collected from medical charts. The distribution and intensity of ET-1 and ET-RA immunostaining in renal biopsies were determined by immunohistochemistry and these correlated with the estimated glomerular filtration rate (eGFR) and proteinuria.
  
  
  RESULTS
  Patients with DN and IgA nephropathy on biopsy had markedly increased staining for ET-1 in endothelial cells of glomerular and peritubular capillaries when compared with controls (p < 0.001). ET-RA staining was also more intense and more diffuse in DN and IgA nephropathy than in controls (p = 0.019) and was restricted to tubular epithelial cells. A positive correlation was observed between ET-1 expression and proteinuria (r = 0.634, p = 0.027), but both ET-1 and ET-RA expressions did not correlate with eGFR.
  
  
  CONCLUSIONS
  In this preliminary report, the higher expressions of ET-1 and ET-RA found in both DN and IgA nephropathy suggest a potential role for the endothelin system in DN as well as in other nondiabetic glomerular diseases.
authors.affiliation: Post-Graduate Endocrinology Program, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Claudete Maria
authors.initials: CM
authors.lastname: Zanatta
authors.forename: Francisco Veríssimo
authors.initials: FV
authors.lastname: Veronese
authors.forename: Melina da Silva
authors.initials: Mda S
authors.lastname: Loreto
authors.forename: Denise A
authors.initials: DA
authors.lastname: Sortica
authors.forename: Virna Nowotny
authors.initials: VN
authors.lastname: Carpio
authors.forename: Maria Isabel Albano
authors.initials: MI
authors.lastname: Eldeweiss
authors.forename: Vinicius Duval
authors.initials: VD
authors.lastname: da Silva
authors.forename: Tiago Giuglianni
authors.initials: TG
authors.lastname: Lopes
authors.forename: Jorge Luiz
authors.initials: JL
authors.lastname: Gross
authors.forename: Luis Henrique
authors.initials: LH
authors.lastname: Canani
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D003430:Cross-Sectional Studies; D003928:Diabetic Nephropathies / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D018450:Disease Progression; D019332:Endothelin-1 / Q000096:biosynthesis* / Q000276:immunology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D007668:Kidney / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D044022:Receptor, Endothelin A / Q000096:biosynthesis* / Q000276:immunology; D012189:Retrospective Studies
chemical_list: D015415:Biomarkers; D019332:Endothelin-1; D044022:Receptor, Endothelin A