In the stomach, parietal cells are responsible for acid production. They react not only to the body's own messenger molecules, but also to bitter-tasting food constituents such as caffeine. A research team has now carried out a study on a human gastric cell line. Their results help to clarify the molecular regulatory mechanisms by which bitter substances influence gastric acid production. It is known that taste receptors for bitter substances are not only found on the tongue, but also on the surface of other tissues and cells. These include the parietal cells of the stomach, which secrete protons into the...