A recent investigation published by Scott Ferguson and colleagues shows for the first time that five days of dietary nitrate supplementation via beetroot juice improves exercise tolerance in a mouse model of sickle cell disease.
Recent work completed by an assistant professor of kinesiology and exercise sciences at the University of Hawai‘i at Hilo was published in the Journal of Applied Physiology on July 23, 2020. Scott Ferguson and his research team are investigating the use of dietary nitrate supplementation to increase nitric oxide availability to improve cardiovascular function during exercise in patients with sickle cell disease (SCD).
“This paper shows for the first time that five days of dietary nitrate supplementation via beetroot juice improves exercise tolerance in a mouse model of SCD,” says Ferguson.
Sickle cell disease impairs the ability to deliver oxygen to muscles during exercise due, in part, to reduced availability of a potent molecule called nitric oxide (NO). NO tells blood vessels to relax and widen, making blood flow easier through them, “sort of like turning on the faucet at your house to let water flow through the plumbing into your sink,” Ferguson explains. Patients with this disease have severe exercise intolerance that often prevents them from participating in routine daily tasks for fear of causing small, painful blood clots, which can occur anywhere in the body.
To determine exercise performance, Ferguson and the research team used the speed-duration relationship (also known as the critical speed), which is a cross-species way to assess running performance. “We like using the critical speed in preclinical studies because the relationship holds true in both humans and animals, helping us translate findings in animal models into the clinical population as quickly as possible,” Ferguson says.
The next task is to uncover precisely how nitrate supplementation is working in these mice and determine the most effective way to employ it for the treatment of SCD.
“Our long-term goal is to develop a nitrate-based therapy that would reduce the risk for vaso-occlusive crises and improve cardiovascular function and quality of life for these patients,” says Ferguson.
Funding and support
Funding for the research has been recently secured through Hawai‘i’s IDeA Networks of Biomedical Research Excellence (INBRE) program to continue some of this work at UH’s John A. Burns School of Medicine, which will provide students within the UH Hilo College of Natural and Health Sciences and the Department of Kinesiology and Exercise Sciences the opportunity to participate in cutting edge preclinical research and potentially pursue careers in medicine and science.
“We currently have our sights set on securing more funding through the National Institutes of Health with another grant proposal this fall, which will help us make a lasting impact with this type of work,” Feguson says.
Story by Susan Enright, a public information specialist for the Office of the Chancellor and editor of UH Hilo Stories. She received her bachelor of arts in English and certificate in women’s studies from UH Hilo.