Regulation of interstitial fluid flow in adventitia along vasculature by heartbeat and respiration

Hongyi Li; Bei Li; Wenqi Luo; Xi Qi; You Hao; Chaozhi Yang; Wenqing Li; Jiazheng Li; Zhen Hua; Tan Guo; Zhijian Zheng; Xue Yu; Lei Liu; Jianping Zhao; Tiantian Li; Dahai Huang; Jun Hu; Zongmin Li; Fang Wang; Hua Li; Chao Ma; Fusui Ji

doi:10.1016/j.isci.2024.109407

Regulation of interstitial fluid flow in adventitia along vasculature by heartbeat and respiration

iScience. 2024 Mar 4;27(4):109407. doi: 10.1016/j.isci.2024.109407. eCollection 2024 Apr 19.

Authors

Hongyi Li^{1

2}, Bei Li¹, Wenqi Luo³, Xi Qi⁴, You Hao⁵, Chaozhi Yang⁶, Wenqing Li¹, Jiazheng Li⁷, Zhen Hua⁷, Tan Guo⁸, Zhijian Zheng⁹, Xue Yu¹⁰, Lei Liu¹¹, Jianping Zhao¹⁰, Tiantian Li¹⁰, Dahai Huang², Jun Hu^{12

13}, Zongmin Li⁶, Fang Wang¹⁰, Hua Li⁵, Chao Ma^{14

15}, Fusui Ji¹⁰

Affiliations

¹ Research Center for Interstitial Fluid Circulation, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing 100730, P.R. China.
² Department of Geriatrics, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing 100730, P.R. China.
³ Department of Cardiac Surgery, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing 100730, P.R. China.
⁴ Peking University Fifth School of Clinical Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing 100730, P.R. China.
⁵ Institute of Computing Technology, Chinese Academy of Sciences, Beijing 100190, P.R. China.
⁶ School of Computer Science and Technology, China University of Petroleum (East China), Qingdao 266580, P.R. China.
⁷ Department of Anesthesiology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing 100730, P.R. China.
⁸ Department of Radiology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing 100730, P.R. China.
⁹ Department of Acupuncture, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing 100730, P.R. China.
¹⁰ Department of Cardiology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing 100730, P.R. China.
¹¹ Department of Pharmacy, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing 100730, P.R. China.
¹² Key Lab of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201210, P.R. China.
¹³ Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, P.R. China.
¹⁴ Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Peking Union Medical College, Beijing 100005, P.R. China.
¹⁵ Chinese Institute for Brain Research, Beijing 100005, P.R. China.

Abstract

Converging studies showed interstitial fluid (ISF) adjacent to blood vessels flows in adventitia along vasculature into heart and lungs. We aim to reveal circulatory pathways and regulatory mechanism of such adventitial ISF flow in rat model. By MRI, real-time fluorescent imaging, micro-CT, and histological analysis, ISF was found to flow in adventitial matrix surrounded by fascia and along systemic vessels into heart, then flow into lungs via pulmonary arteries and back to heart via pulmonary veins, which was neither perivascular tissues nor blood or lymphatic vessels. Under physiological conditions, speckle-like adventitial ISF flow rate was positively correlated with heart rate, increased when holding breath, became pulsative during heavy breathing. During cardiac or respiratory cycle, each dilation or contraction of heart or lungs can generate to-and-fro adventitial ISF flow along femoral veins. Discovered regulatory mechanisms of adventitial ISF flow along vasculature by heart and lungs will revolutionize understanding of cardiovascular system.

Keywords: Animal physiology; Biological sciences; Physiology.