Peng Hu1, Xue Qi Zhao2, Jing Wang2, Hai Bo Kong2, Bo Hu2, Ling Lu2, Yuan Han Qin3. 1. Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, China hupeng28@sohu.com. 2. Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, China. 3. Department of Pediatrics, The First Affiliated Hospital of Guangxi Medical University, China.
Abstract
INTRODUCTION: 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.
INTRODUCTION: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.