F-18 FDG PET/CT CAN BE USED AS AN IMAGING BIOMARKER FOR REFLECTING SYNTHETIC VASCULAR SMOOTH MUSCLE CELL ACTIVITY IN THE ANIMAL MODEL OF VASCULAR REMODELING DISORDER

Abstract

Objective: Synthetic vascular smooth muscle cells (VSMCs) play important roles in vascular remodeling disorders including atherosclerosis, restenosis, and transplant vasculopathy. 18F-fluorodeoxyglucose positron emission tomography (F-18 FDG PET/CT) is a non-invasive molecular imaging modality widely used in clinical practice for reflecting glucose metabolism. The aim of this study was to demonstrate the feasibility of measuring the activity of synthetic VSMCs using F-18 FDG PET/CT in an atherosclerotic rat model of partial carotid artery ligation. Design and method: Using Sprague-Dawley rats, neointimal hyperplasia was made by right partial carotid ligation method. After 1 month, all animal models undertook F-18 FDG PET/CT images. Then the vessels were harvested and analyzed with autoradiography and histomolecular approaches. Results: The affected carotid artery exhibited prominent neointinal hyperplasia region with a narrowed lumen. Known surrogate marker of synthetic VSMCs including matrix metallopeptidase-9, cyclophilin A, and collagen type III were increased in neointimal hyperplasia region. There were no immune cells such as macrophages or neutrophils. F-18 FDG PET/CT and autoradiography showed increased tracer uptake along the same affected arteries. Glucose transporter-1 was also increased in neointimal hyperplasia region. Conclusions: It is feasible to use F-18 FDG PET/CT as an imaging surrogate-marker for reflecting synthetic VSMC activities in vascular remodeling disorders.