Low frequency electrical impulses reduce atherosclerosis in cholesterol fed rabbits.

BACKGROUND: This investigation studied whether low frequency electrical impulses (EI) induce or prevent development of new atherosclerotic plaque in previously diseased vessels. MATERIAL/METHODS: In all rabbits, an electrode was sutured to the left psoas major muscle close to the upper part of the abdominal aorta (AA), and a pacemaker was implanted on the opposite side of the AA just below diaphragm. Group 1 received a high cholesterol diet (HCD) to induce atherosclerosis but no EI (control). Euthanasia followed after 3 weeks (series I), 8 weeks (series II) and 11 weeks (series III) of HCD. In series IV animals received HCD alone for 3 weeks then EI was added to the HCD for another 8 weeks (weeks 4-11) at a rate of 30 impulses per minute (IPM) at 3V. Euthanasia followed after 11 weeks. Atherosclerotic thickness grades were assigned using a 0 (low) to 4 (high) grading system, and the surface area involved in disease was calculated. RESULTS: In control rabbits, after 11 weeks of HCD atherosclerotic thickness grade in lower abdominal aorta was 1.68 +/-0.25. In rabbits exposed to EI (30 IPM at 3V) this grade was 0.5+/-0.37 (p<0.05). The involved surface area was only 8.5+/-4.69% (series IV) vs. 32.5+/-4.0 % in control CONCLUSIONS: When applied near the AA, electrical impulses (30 IPM at 3V) decrease atherosclerotic deposits despite continuation of a high cholesterol diet.

Complete vascular healing and sustained suppression of neointimal thickening after local delivery of advanced c-myc antisense at six months follow-up in a rabbit balloon injury model.

BACKGROUND: Neointimal hyperplasia following percutaneous transluminal coronary angioplasty (PTCA) is one of the major components of the process of restenosis. We evaluated the long-term impact of local delivery of c-myc neutrally charged antisense oligonucleotides (Resten-NG) upon neointimal formation following PTCA in a rabbit model. METHODS: PTCA was performed in the iliac arteries of 10 New Zealand white rabbits at 8 atm for 30 s, three times. An infusion of 500 micro g Resten-NG (n=6) or saline (n=4) was delivered to the site at 2 atm via the outer balloon pores of the transport catheter over 2 min. The diet was supplemented with 0.25% cholesterol for 10 days before and 6 months following PTCA. RESULTS: After 6 months, animals were sacrificed and vessels were fixed in formalin, processed and stained with hematoxylin, eosin, and movat. Histological analysis revealed complete vascular healing in both groups of animals. Planimetry showed that intimal areas were 1.71+/-0.25 and 0.65+/-0.36 mm2 in the control and antisense delivery groups, respectively (P<.05). CONCLUSION: We conclude that local delivery of Resten-NG significantly inhibited neointimal thickening following PTCA in a rabbit for up to 6 months.