Author + information
Arterial restenosis after angioplasty or stent placement has hindered the treatment of coronary artery disease, particularly in diabetics. We have theorized that the antiproliferative agents gastrin-releasing peptide (GRP) antagonists and growth hormone-releasing hormone (GHRH) antagonists, might decrease neointimal hyperplasia and restenosis in diabetic rats after carotid balloon injury.
Zucker type II obese rats were divided into three groups. Group 1 (control) received the peptide Cetrorelix, a luteinizing hormone-releasing hormone (LHRH) antagonist (250 mcg/kg/day) not thought to be involved in restenosis. Group 2 received the GRP antagonist RC-3695 (250 mcg/kg/day). Group 3 received the GHRH antagonist MZ-4-71 (250 mcg/kg/day). The common carotid arteries were injured with a 2F Fogarty catheter. Animals were sacrificed after thirty days, carotid arteries cut every 5 mm from the aortic arch to the carotid bifurcation and embedded in paraffin for staining with hematoxylin-eosin or trichrome. The media area, intima area, intima to media area ratio (I/M), and the percent (%) area of stenosis were calculated.
Control I/M area, 2.38 + 1.09, GRP antagonist I/M area, 1.63 + 0.41 (p<0.005). Control % area of stenosis, 93.09% + 10.83, GRP antagonist % area stenosis, 98.78% + 1.48 (p<0.01). GHRH antagonist group: I/M area, 1.33 + 0.58 (p<0.0005 vs. control) % area stenosis 78.84% + 24.97 (p<0.05 vs. control). Thus, GRP antagonist resulted in a net increase in medial area which resulted in no change in % area stenosis in spite of the reduction in I/M area. However, GHRH antagonist resulted in a significant decrease in the I/M area and % area stenosis.
The significant decrease in the IM ratio and % area of stenosis in the GHRH antagonist group support the hypothesis that this peptide may reduce neointimal hyperplasia and restenosis. Further research will extend the findings on the potential influence these peptides may have on the degree of restenosis after arterial injury.
Poster Sessions, Expo North
Sunday, March 10, 2013, 9:45 a.m.-10:30 a.m.
Session Title: Anti-Ischemic Therapies
Abstract Category: 9. Chronic CAD/Stable Ischemic Heart Disease: Basic
Presentation Number: 1194-67
- 2013 American College of Cardiology Foundation