A study conducted by University of Missouri researchers has identified the impact of Type 2 diabetes on lymphatic vessels, a finding that could lay the groundwork for new therapies to improve the lives of people with Type 2 diabetes, according to an article posted July 14 to MU Health, the University of Missouri Health System Magazine.
“The lymphatic system’s primary role is to transport lymph — a clear fluid that contains white blood cells that help rid the body of antigens or destroy cancer cells — to lymph nodes where immune responses are activated,” Joshua Scallan, PhD, a research assistant professor of medical pharmacology and physiology at the MU School of Medicine, said in the article. “We now know for the first time that when individuals have Type 2 diabetes, the walls of their lymphatic vessels are defective and become increasingly permeable, or leaky.”
The study, “Lymphatic vascular integrity is disrupted in Type 2 diabetes due to impaired nitric oxide signaling,” was published online April 7 by Cardiovascular Research, the international basic science journal of the European Society of Cardiology.
Scallan likens the permeability of a healthy lymphatic vessel to a porous garden hose, which is designed to allow water to escape through small holes in the hose. A defective lymphatic vessel in a person with Type 2 diabetes has larger holes, which lets too much water escape so lymph and antigens are not transported to the lymph nodes, according to the article.
New investigative method
While studying lymphatic vessel function in animals in the past has been a challenge for researchers because lymph vessels are clear and appear almost invisible, Scallan developed a new investigative method to measure lymphatic vessel permeability. The research discovered vessels in diabetic, leptin receptor-deficient (db/db) mice produced nitric oxide levels much lower than healthy lymphatic vessels.
“When an individual has Type 2 diabetes, cells in the lymphatic vessels aren’t producing enough nitric oxide, which is essential to maintaining the integrity of their endothelial layer so that they function properly,” Scallan said in the article. “We found that by giving the lymphatic vessels L-arginine, an amino acid commonly found in red meat, poultry, dairy products and nutritional supplements, we were able to boost their nitric oxide production and restore their ability to act as a barrier.”
While more studies are needed, Scallan believes the findings could lead to further research for developing new treatments or therapies for individuals with Type 2 diabetes.
In addition to Scallan, the research team includes Michael Hill, Ph.D., professor in the MU Department of medical pharmacology and physiology, and Michael Davis, PhD, Margaret Proctor Mulligan professor in Medical Research in the MU department of medical pharmacology and physiology. •