Microangiography system for investigation of metabolic syndrome in rat model using synchrotron radiation

Metabolic syndrome refers to a clustering of cardiovascular disease risk factors. We investigated the characteristics of vascular endothelial function in coronary arteries of rats using a microangiography technique. For this study, we developed a microangiography system using a real-time imaging system and a third generation synchrotron radiation source at SPring-8. An X-ray direct-conversion type detector with 6-μm spatial resolution was used for real-time biomedical imaging. For synchrotron radiation radiography, a long source-to-object distance and a small source spot can produce high-resolution images. Microangiographic images were obtained without image blurring and were stored in a digital frame memory system at a maximum speed of 30 frame/s with a 1024 × 1024-pixel, 10-bit format. The vasorelaxation response in the coronary arteries was determined using coronary microangiography of ex vivo beating hearts for evaluating vascular endothelial dysfunction in metabolic syndrome. In imaging experiments, the small coronary arteries were visualized after iodine contrast agent injection into the coronary artery. We assessed the magnitude of coronary artery vasorelaxation before and after administration of drugs that modulate endothelial control of the coronary arteries in the rat model.