Cyuan‑Cin Liua, Wei‑Min Liub, Hsien‑Tsai Wua, Chien‑Hsing Wangc, An‑Bang Liud*
aDepartment of Electrical Engineering, National Dong Hwa University, Hualien, Taiwan, bDepartment of Computer Science and Information Engineering, National Chung Cheng University, Chiayi, Taiwan, cDepartment of Surgery, Buddhist Tzu Chi General Hospital, Hualien, Taiwan, dDepartment of Neurology, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan
Open Access funded by Buddhist Compassion Relief Tzu Chi Foundation
Objective: Endothelial dysfunction is the earliest change in atherosclerosis. Flowmediated dilatation (FMD) is used to assess endothelial function in humans. However, this assessment is not easy in small animals. This study demonstrated the reliability and reproducibility of a proposed instrument for in vivo assessment of FMD in a rodent model using infrared pulse sensors. Materials and Methods: We used 24 adult male Wistar Kyoto rats randomly divided into three groups. FMD was measured under continuous infusion of normal saline followed by intra‑arterial infusion of acetylcholine (Ach; n = 8), sodium nitroprusside (SNP; n = 8), or Nω‑nitro‑L‑arginine methyl ester (L‑NAME; n = 8). Results: The dilatation indices (DIs) of all three groups were similar before application of the vasoactive agents (1.82 ± 0.46, 1.81 ± 0.44, and 1.93 ± 0.40, P = 0.877, by one‑way analysis of variance). The DI was significantly increased during infusion of Ach (2.97 ± 1.03 vs. 1.82 ± 0.46, P = 0.015), unchanged during infusion of SNP (1.81 ± 0.44 vs. 1.98 ± 0.40, P = 0.574), and attenuated during infusion of L‑NAME (1.91 ± 0.40 vs. 1.42 ± 0.35; P = 0.028). Conclusion: The results of this study correlated well with those of human studies, suggesting that this method can be used for in vivo evaluation of endothelial function in small animals.
Keywords: Endothelial function, Flow‑mediated dilatation, Nitric oxide