Abstract
Flow-mediated dilation (FMD) is widely used to diagnose atherosclerosis in its early stage. In FMD, the amount of arterial dilation is assumed to reflect the amount of nitric oxide secreted by endothelial cells (ECs), and thus, healthiness of ECs function. However, the reproducibility of FMD is not enough in some cases, and detailed understanding of these phenomena is necessary. To measure the details of FMD response, we have developed animal FMD model in rabbit common carotid arteries to observe diameter, blood pressure and flow rate directly. We evaluated FMD before and after collapse of the artery. And also, areas of individual ECs and volume of glycocalyx layer on the ECs were measured with a scanning electron microscopy and a fluorescence microscopy , respectively. Collapse of the artery caused significant decrease in FMD (P<0.05), and in the volume of glycocalyx layer per cell (P<0.05), while cell area was increased (P<0.05) possibly because of detachment of some ECs from the intima and its recovery. These results suggest that in situ FMD model we have developed might reproduce FMD response correctly and the decrease of FMD might be caused by decrease of EC function.
