Objective:To discuss the potential role of C-type natriuretic peptide(CNP) on occurrence of vascular restenosis after percutaneous transluminal angioplasty(PTA).Methods:CNP expression was detected with RT-PCR

real-time quantitative RT-PCR

Western blot and immunohistochemistry after PTA in iliac artery in rabbit model of atherosclerosis.Reconstructed plasmid pcDNA3.1(+)/hCNP was transfected with polyethylenimine in iliac artery to investigate the effect of CNP over-expression on post-PTA restenosis.Results:CNP expression decreased markedly 2 and 4 weeks after PTA.The relative levels of CNP mRNA expression revealed with RT-PCR were 0.38±0.06 vs 0.98±0.15 and 0.43±0.05 vs 1.01±0.12(P<0.001).With real-time quantitative RT-PCR

Ct value ratios were 2.06±0.17 vs 1.27±0.10 and 2.10±0.11 vs 1.23±0.10(P<0.001).The relative levels of CNP protein expression detected with Western blot were 0.15±0.03 vs 0.31±0.06 and 0.13±0.04 vs 0.30±0.05(P<0.001).A lighter dyeing was identified in PTA group in both 2 weeks and 4 weeks with immunohistochemistry.CNP mRNA and protein expressions were not different on 8-week spot between PTA and non-PTA groups.Hyperplasia and restenosis rate after PTA declined significantly in CNP over-expression group compared with non-transfected one(0.29±0.07 vs 0.76±0.06;0.31±0.02 vs 0.57±0.05

P<0.001).Conclusion:CNP down-expression may be one of the reasons to induce post-PTA restenosis.CNP gene transfection is potential to prevent vascular restenosis.