L-Arginine Supplementation Improves Vascular Endothelial Dysfunction Induced by High-Fat Diet in Rats Exposed to Hypoxia.

Abstract

INTRODUCTION:

Our previous study showed that high-fat diet inhibited the increase in nitric oxide and endothelial nitric oxide synthase expression in the aortic endothelium of rats exposed to hypoxia, and hypoxia plus a high-fat diet led to earlier and more severe vascular endothelial dysfunction (VED) than hypoxia alone. The purpose of the present study was to investigate the effects of L-arginine on high-fat diet-induced VED of rats in hypoxia.

METHODS:

Forty male Sprague-Dawley rats were randomly divided into 4 groups and treated with hypoxia (H group), hypoxia plus high-fat diet (H+HFD group), hypoxia plus L-arginine (H+L-Arg group), and hypoxia plus high-fat diet and L-arginine (H+HFD+L-Arg group) for 1 wk. Hypoxia was simulated in a hypobaric chamber with an altitude of 5000 m. Aortic morphology and endothelium-dependent vasorelaxation were used to assess VED.

RESULTS:

High-fat diet impaired vascular remodeling and reduced endothelium-dependent vasodilator response to acetylcholine in rats exposed to hypoxia, secondary to dysregulation of the nitric oxide pathway. L-arginine supplementation significantly increased plasma nitrates and nitrites and endothelial nitric oxide synthase mRNA levels and improved ultrastructural changes in aortic endothelium and endothelium-dependent vasodilator response.

CONCLUSIONS:

L-arginine prevents aortic ultrastructural changes and reverses VED induced by high-fat diet in rats exposed to hypoxia, which may have implications for VED induced by high-fat diet in high altitude dwellers.

• Authors: Yan-Xia Zhao, Li Tong, Guang-Mei Zhang, Xie-Hui Zhao, Yu-Ping Sa, Yan Liu, Dian-Xiang Lu, Qin Ga, Ping Wu
• Journal: Wilderness & environmental medicine (Wilderness Environ Med) Vol. 31 Issue 4 Pg. 400-406 (Dec 2020) ISSN: 1545-1534 [Electronic] United States
• PMID: 33132032 (Publication Type: Journal Article)
• Copyright: Copyright © 2020. Published by Elsevier Inc.

Chemical References

• RNA, Messenger
• Nitric Oxide
• Malondialdehyde
• Arginine
• Superoxide Dismutase

Topics

• Animals
• Aorta (drug effects)
• Arginine (administration & dosage, pharmacology)
• Body Weight (drug effects)
• Diet, High-Fat (adverse effects)
• Dietary Supplements
• Endothelium, Vascular (drug effects)
• Hypoxia
• Male
• Malondialdehyde (blood)
• Nitric Oxide (blood)
• RNA, Messenger
• Random Allocation
• Rats
• Rats, Sprague-Dawley
• Superoxide Dismutase (blood)