Nitric Oxide Again, Alzheimer's
Nitric oxide production may be linked with longevity in calorie restricted mice, but it's not good in the brain: "An enzyme [iNOS] that triggers the production of nitric oxide (NO) - a gas that helps immune cells fight off invading pathogens - accelerates the formation of brain lesions in Alzheimer's-prone mice ... For nearly a decade, researchers have known that iNOS was present in the brain lesions of patients with Alzheimer's disease, but nobody had addressed whether its presence was making the disease worse. Nathan and colleagues now show that Alzheimer's-prone mice that lack iNOS live twice as long and develop fewer brain lesions than iNOS-expressing mice." Biochemistry is a complicated business, but snapshots like this fail to show the bigger picture: roiling, energetic progress in understanding and knowledge.
Link: http://www.eurekalert.org/pub_releases/2005-10/joem-gms102005.php