1. Department of Cardiology, Peking Union Medical College Hospital (PUMCH), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China.
2. Laboratory of Hainan Trauma and Disaster Rescue, The First Affiliated Hospital of Hainan Medical University, Haikou 571199, China.
3. Key Laboratory of Emergency and Trauma, Ministry of Education, Engineering Research Center for Hainan Bio-Smart Materials and Bio-Medical Devices, Key Laboratory of Hainan Functional Materials and Molecular Imaging, College of Emergency and Trauma, Hainan Medical University, Haikou 571199, China.
4. Experimental Research Center, China Academy of Chinese Medical Sciences, Beijing 100700, China.
5. Department of Cardiology, the Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250000, China.
For salt-sensitive hypertension (SSH), salt restriction and angiotensin-converting enzyme (ACE) inhibitors are essential treatments, but their effect on the function of resistance arteries is unclear. Here, we present an intravital study to detect the effect of salt restriction and ACE inhibitors on the function of the mesenteric small artery (MSA) in SSH. Dahl salt-sensitive rats were randomized into the following groups: ACE inhibitor gavage, salt restriction, ACE inhibitor combined with salt restriction, and high-salt diet. After a 12-week intervention, the mesenteric vessels maintained their perfusion in vivo, and the changes in the diameter and blood perfusion of the MSAs to norepinephrine (NE) and acetylcholine (ACh) were detected. Switching from a high-salt diet to a low-salt diet (i.e., salt restriction) attenuated the vasoconstriction of the MSAs to NE and promoted the vasodilatation to ACh, while ACE inhibitor improved the vasodilatation more obviously. Pathologically, changes in local ACE, AT1R, and eNOS expression were involved in these processes induced by a high-salt diet. Our study suggests that salt restriction and ACE inhibitor treatment improve high salt intake-induced MSA dysfunction in SSH, and salt restriction is a feasible and effective treatment. Our findings may provide a scientific basis for the treatment of hypertension.
Keywords: Hypertension, salt intake, salt restriction, mesenteric small artery, vascular reactivity, angiotensin-converting enzyme (ACE) inhibitor