Researchers have identified an enzyme located in the inflammatory cells of the body which is responsible for vascular damage caused by aircraft noise.

Various studies have shown that long term exposure to aircraft noise can lead to increased development of cardiovascular diseases. The findings showed that removal of the enzyme phagocytic NADPH oxidase, completely prevents vascular damage. "Elimination of the enzyme phagocytic NADPH oxidase, which is located mainly in inflammatory cells, completely avoids aircraft noise-induced negative effects on vessels and brain," said Thomas Munzel, Professor at the Johannes Gutenberg University-Mainz (JGU) in Germany.

In the study, published in the European Heart Journal, the team was also able to show that night-time noise has a particularly harmful effect and thus demand it should be protected from noise. "We demonstrate for the first time that 'night-time noise', i.e., noise during the sleep phase of the mice, and not the noise during the waking phase is responsible for vascular dysfunction," added Professor Andreas Daiber from the JGU.

Further, the scientists also examined the effects of aircraft noise on the brain. They identified neuronal nitric oxide (NO) synthase -- an important enzyme in the brain that is responsible for learning and memory. This enzyme is down-regulated by aircraft noise and its function gets impaired, explaining the cognitive developmental disorders in children after exposure to aircraft noise, the researchers said.

Further, the team also found that transcription factor -- protein that helps turn certain genes on or off by binding them to DNA -- named FoxO3, also plays a central role in noise-induced vascular and brain damage. The down-regulation of this transcription factor by night-time noise leads to a defective gene expression network that controls cellular events as a function of circadian rhythm. The researchers explained that disturbance to the circadian rhythm is linked with sleep disorders and subsequently to more cardiovascular, mental and metabolic disorder. The findings "may enable us to develop drug strategies to reduce the negative effects of aircraft noise for our body," the researchers said.