Zhukov Oleg, Postnov Dmitry D, Hejn Kamilla H, Ravnskjaer Kim, Sosnovtseva Olga
Department of Biomedical Sciences, University of Copenhagen , Copenhagen, Denmark.
Center of Functionally Integrative Neuroscience, University of Aarhus, Aarhus, Denmark.
Biomed Opt Express. 2025 Mar 4;16(4):1299-1309. doi: 10.1364/BOE.554663. eCollection 2025 Apr 1.
The liver controls blood homeostasis and depends critically on adequate blood supply. While the global regulation of liver blood flow via the hepatic arterial buffer response is well established, the mechanisms governing hepatic sinusoidal hemodynamics remain elusive. We use laser speckle contrast imaging to investigate the hepatic microvascular blood flow in anesthetized rats. Laser speckle contrast imaging offers a spatial resolution of a few micrometers, enabling visualization of individual microvessels, and a temporal resolution sufficient to track flow dynamics. This allowed us to resolve individual sinusoids and venules on the liver surface and to detect a reduction of the blood flow following local Angiotensin II injections. We show that the microvascular blood flow oscillates with frequencies within the range of 0.05-0.4 Hz, which may be linked to rhythmic contraction of upstream blood vessels. Our findings provide insights into vessel-specific liver microcirculation , offering new opportunities to explore vascular dysfunction mechanisms in metabolic liver diseases.
肝脏控制着血液稳态，并且严重依赖充足的血液供应。虽然通过肝动脉缓冲反应对肝脏血流的整体调节已得到充分证实，但控制肝窦血流动力学的机制仍不清楚。我们使用激光散斑对比成像来研究麻醉大鼠的肝脏微血管血流。激光散斑对比成像提供了几微米的空间分辨率，能够可视化单个微血管，并且具有足以跟踪血流动力学的时间分辨率。这使我们能够分辨肝脏表面的单个肝窦和小静脉，并检测局部注射血管紧张素II后血流的减少。我们发现微血管血流以0.05-0.4Hz范围内的频率振荡，这可能与上游血管的节律性收缩有关。我们的研究结果为特定血管的肝脏微循环提供了见解，为探索代谢性肝病中的血管功能障碍机制提供了新的机会。
