natriuretic-peptide--c-type and Carotid-Stenosis

Long-term intravenous infusion of high-dose C-type natriuretic peptide (CNP) is known to prevent neointimal formation after vascular injury. Ultrasound (US) irradiation during microbubbles (MBs) infusion (US/MBs) has been used for local delivery of bioactive agents. We examined whether short-term infusion of CNP could also inhibit neointimal development and whether combined US/MBs treatment at the beginning of the CNP infusion could enhance its effect.. In the rat carotid artery-balloon injury model, the intima/media area (I/M) ratio 14 days after injury was compared among various short-term post-injury treatments. For combined US/MBs, a commercial echocardiograph (1.8 MHz, mechanical index 1.0) and albumin-coated octafluoropropane gas MBs were used.. Infusion of high-dose CNP (1.0 microg/kg/min) immediately after injury for only 24 h successfully reduced the I/M ratio (0.18+/-0.05) to 18% of the ratio in control rats (1.00+/-0.13) that underwent only balloon injury. Although low-dose CNP (0.1 microg/kg/min for 24 h) alone was not effective in reducing the I/M ratio (0.83+/-0.18), combined US/MBs treatment for the first 80 min of the infusion markedly reduced the I/M ratio (0.17+/-0.07), which persisted until 28 days after injury (0.16+/-0.04).. The effects of CNP on the events occurring early after arterial injury may be important in preventing subsequent neointimal development. Thus, intravenous infusion of CNP with US/MBs at its initiation may provide a clinically feasible anti-restenosis therapy applicable immediately after vascular interventions.

Topics: Analysis of Variance; Animals; Carotid Artery Injuries; Carotid Stenosis; Catheter Ablation; Combined Modality Therapy; Cyclic GMP; Male; Natriuretic Peptide, C-Type; Rats; Rats, Sprague-Dawley; Tunica Intima; Ultrasonic Therapy; Ultrasonography