A hormone secreted by cells throughout the body and known to play a role in cardiovascular disease and other cell functions is also critical for proper formation of the lymphatic system in mice, according to research from the University of North Carolina at Chapel Hill School of Medicine.
By targeting this hormone, called adrenomedullin, researchers may be able to treat the more than 100 million people worldwide affected by lymphedema, a condition that causes painful swelling in arms and legs.
“Our research also may lead to therapies to prevent cancer cells from traveling through these lymphatic vessels to infiltrate other parts of the body,” said Kathleen M. Caron, senior study author and assistant professor of cell and molecular physiology and genetics at UNC.
Adrenomedullin is a powerful vascular peptide that can widen existing blood vessels and even promote the growth of new ones. But it also has many more functions, such as helping control metabolism, heart rate, thirst and appetite, stress response, antibacterial activity and nerve signal transmission.
The study, published Dec. 20, 2007, in the Journal of Clinical Investigation, demonstrates that this peptide is necessary for yet another function in our bodies: without it, our lymphatic system – an important part of the body's immune system – does not form normally. The lymphatic system includes lymph nodes and a network of thin tubes that transport fluid and immune cells that have leached out of tissues back into the circulatory system. These tubes branch, like blood vessels, into all the tissues of the body. Between two and three liters of the almost colorless fluid called lymph go through the lymphatic system in a day.