Red blood cell endothelial cells. Exposure of red blood cells to physiological levels of shear stress activates nitric oxide synthase and export of nitric oxide, which may contribute to the regulation of vascular tonus. Red blood cells can also produce hydrogen sulfide, a signalling gas that acts to relax vessel walls. It is believed that the cardioprotective effects of garlic are due to red blood cells converting its sulfur compounds into hydrogen sulfide. Red blood cells also play a part in the body's immune response: when lysed by pathogens such as bacteria, their hemoglobin releases free radicals, which break down the pathogen's cell
Red as Blood, or Tales from the Sisters Grimmer Red as Blood, or Tales from the Sisters Grimmer Red as Blood, or Tales from the Sisters Grimmer is a short story collection of dark fantasy retellings of popular fairytales by British author Tanith Lee. Contrary to what the title may suggest, it not only includes retellings of fairytales by the Brothers Grimm, but also by Charles Perrault, Gabrielle-Suzanne Barbot de Villeneuve or Alexander Afanasyev. The title story was nominated for a Nebula Award. "Red as Blood, or Tales from the Sisters Grimmer" contains the following tales: In 2014, the book was released as an expanded edition including a new