Objective: To explore the relationship between hypoxia-inducible foctor-1α (HIF-1α) and neovascularization in early atherosclerosis plaques by establishing rabbit carotid atherosclerosis models, and to observe the value of contrast-enhanced ultrasound in the detection of neovascularization.
Methods: We provided high-fat diet combined with the implantation of silicone rubber ring to establish carotid atherosclerosis in rat models. On the 14th and 28th days, we detected neovascularization in the carotid atherosclerotic plaques by contrast-enhanced ultrasound, obtained the peak intensity (PI) of the contrast agent in the plaques by time-intensity curve (TIC) and analyzed the difference. We also tested the level of HIF-1α, vascular endothelial growth factor (VEGF), cluster of differentiation 31 (CD31), α-actin, and RAM-11 by immunohistochemical method in each group, analyzed their correlation, and the correlation between PI and CD31 expression.
Results: On the 14th day, contrast-enhanced ultrasound showed the neovascularization in the carotid atherosclerotic plaques. On the 14th and 28th days, the intensity of contrast-enhanced ultrasound showed significant difference, the mean optical density of HIF-1α, VEGF, CD31, RAM-11, and α-actin within the carotid atherosclerotic plaques also showed statistical difference. The expressions between HIF-1α and VEGF, HIF-1α and CD31, HIF-1α and RAM-11, HIF-1α and α-actin, as well as PI and CD31 showed highly positive correlations.
Conclusion: During the process of atherosclerosis evolution, neovascularization in the atherosclerotic plaques has come into being in the early period, and HIF-1α in early atherosclerosis can promote the formation of neovascularization. Contrast-enhanced ultrasound can detect the dynamic changes of neovascularization within early atherosclerotic plaques.