Graphical Abstract. Credit: Function (2024). DOI: 10.1093/function/zqae042

A new study in rats shows that lactate, a substance found in the muscles, initiates a cascade of actions in the muscles that helps blood vessels relax. The surprising results are published ahead of print in the journal Function.

Lactate, also known as lactic acid, is a byproduct that comes from the process of breaking down sugar and other carbohydrates. Lactic acid builds up in the muscles during vigorous exercise.

Researchers sought to understand how skeletal muscle tissue around the blood vessels could influence how the vessels behave. They analyzed RNA, mitochondria and lactate levels from artery and muscle samples from rats to determine the vessels’ vascular tone. The research team found that lactate in the arteries released nitric oxide, a substance that limits contraction of blood vessels.

“Healthy skeletal muscles help keep blood vessels relaxed and regulate blood pressure. When muscles are weakened, this process may not work properly, potentially leading to high blood pressure or premature aging of blood vessels. Understanding this link between muscles and blood vessels could lead to new treatments that benefit both skeletal muscle and heart health,” said Camilla Ferreira Wenceslau, Ph.D., corresponding author of the study.