title: Paradoxical expressions of natriuretic peptide receptor-C and neutral endopeptidase account for C-type natriuretic peptide decline during the progression of experimental obstructive nephropathy.
abstract: BACKGROUND
  C-type natriuretic peptide (CNP) selectively binds to the guanylyl cyclase coupled natriuretic peptide receptor (NPR)-B and exerts more potent antihypertrophic and antifibrotic properties. Elimination of CNP occurs mainly by neutral endopeptidase (NEP) and NPR-C.
  
  
  METHODS
  We established a rat model of unilateral ureteral obstruction (UUO) to examine the continuous change of the CNP expression and to assess the correlations of NPR-B, NPR-C, NEP with CNP in the obstructed kidneys.
  
  
  RESULTS
  The expressions of CNP mRNA and protein in the obstructed kidneys tended to be higher immediately after ligation and declined at later time points compared to sham-operated rats, measured by real-time polymerase chain reaction (PCR) and western blot analysis. Subsequent correlation analysis indicated that CNP mRNA was positively correlated with NPR-B mRNA (r=+0.673, p<0.05). In addition, the increased expression of NPR-C (r=-0.943 and -0.837 for mRNA and protein respectively, p<0.05) and NEP (r=-0.687 and -0.823 for mRNA and protein respectively, p<0.05) were accompanied by a signiﬁcant decline in CNP.
  
  
  CONCLUSIONS
  A high level of CNP may contribute to the elevated expression of NPR-B in the early phase of UUO. More interestingly, paradoxical expressions of NPR-C and NEP may account for the decline of CNP in the obstructed kidneys.
authors.affiliation: Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, China hupeng28@sohu.com.
authors.forename: Peng
authors.initials: P
authors.lastname: Hu
authors.affiliation: Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, China.
authors.forename: Xue Qi
authors.initials: XQ
authors.lastname: Zhao
authors.affiliation: Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, China.
authors.forename: Hai Bo
authors.initials: HB
authors.lastname: Kong
authors.affiliation: Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Hu
authors.affiliation: Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Lu
authors.affiliation: Department of Pediatrics, The First Affiliated Hospital of Guangxi Medical University, China.
authors.forename: Yuan Han
authors.initials: YH
authors.lastname: Qin
mesh_terms: D000818:Animals; D015153:Blotting, Western; D018450:Disease Progression; D006801:Humans; D007674:Kidney Diseases / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D020098:Natriuretic Peptide, C-Type / Q000737:chemistry / Q000378:metabolism*; D015260:Neprilysin / Q000378:metabolism*; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D017461:Receptors, Atrial Natriuretic Factor / Q000378:metabolism*; D000099242:Atrial Natriuretic Factor Receptor B
chemical_list: D020098:Natriuretic Peptide, C-Type; D015260:Neprilysin; D017461:Receptors, Atrial Natriuretic Factor; D000099242:Atrial Natriuretic Factor Receptor B; C073616:atrial natriuretic factor receptor C
keywords: C-type natriuretic peptide; natriuretic peptide receptor; neutral endopeptidase; obstructive nephropathy; unilateral ureteral obstruction