Lovelock: Home. Mice Lacking Enzyme Renin Stay Lean On High-fat Diet, With Little Exercise. A new study elucidates the connection between an enzyme involved in blood pressure control and symptoms of the metabolic syndrome. The researchers report in the December issue of Cell Metabolism, a publication of Cell Press, that mice lacking the enzyme known as renin are lean and resistant to gaining weight on a high-fat diet, even though they continue to eat just as much and don't exercise more.
The findings suggest that renin-blocking drugs designed for treating high blood pressure might also improve obesity and insulin resistance, according to the researchers. Renin plays an important rate-limiting role in the production of a hormone called angiotensin II (Ang II) that increases blood pressure by constricting blood vessels. "An overactive renin-angiotensin system has also been associated with obesity and the metabolic syndrome," said Nobuyuki Takahashi of The University of North Carolina at Chapel Hill.
"Now we've gained new insight into the mechanism responsible. " 'Suspended Animation' Induced In Mice With Sewer Gas: Effects Are Reversible. Low doses of the toxic gas responsible for the unpleasant odor of rotten eggs can safely and reversibly depress both metabolism and aspects of cardiovascular function in mice, producing a suspended-animation-like state. In the April 2008 issue of the journal Anesthesiology, Massachusetts General Hospital (MGH) reseachers report that effects seen in earlier studies of hydrogen sulfide do not depend on a reduction in body temperature and include a substantial decrease in heart rate without a drop in blood pressure. "Hydrogen sulfide is the stinky gas that can kill workers who encounter it in sewers; but when adminstered to mice in small, controlled doses, within minutes it produces what appears to be totally reversible metabolic suppression," says Warren Zapol, MD, chief of Anesthesia and Critical Care at MGH and senior author of the Anesthesiology study.
The study was supported by grants from the National Institutes of Health and Linde Gas Therapeutics. Welcome to Mind and Machine Module.