FLICKR, ROSMARYFor years, researchers have reported predictable seasonal variations in human blood pressure. Both systolic and diastolic blood pressure tend to be greatest during the winter months and lowest in the summer. Many have attributed this variation to changes in temperature, but according to a study published in the Journal of Investigative Dermatology today (January 20), variations in sun exposure may be the answer.
“This study . . . provides suggestive evidence that skin-derived NO metabolites may have a role in modulation of blood pressure upon UV exposure,” Thomas Michel, a professor of medicine and biochemistry at Harvard Medical School who was not involved in the work, told The Scientist in an e-mail
The University of Southampton’s Martin Feelisch and his colleagues first began to suspect that sunlight could affect blood pressure nearly two decades ago. At that time, the researchers were investigating the vasodilative effects of nitric oxide (NO), a signaling molecule that circulates in the bloodstream at low concentrations, typically by hitching a ride on proteins, like albumin or hemoglobin.
It was more than 10 years ago that Feelisch and his team first exposed healthy individuals to ...
