The researchers found that the kidney conserves or releases water by balancing levels of sodium, potassium, and the waste product urea. This may be what ties glucocorticoid levels to salt intake. A high salt diet increased glucocorticoid levels, causing muscle and liver to burn more energy to produce urea, which was then used in the kidney for water conservation. That also led the mice to eat more. These salt-driven changes in metabolism may thus partly explain why high salt diets have been linked to diabetes, heart disease, and other health problems that can result from the condition known as metabolic syndrome.
The translation of mRNA can also be controlled by a number of mechanisms, mostly at the level of initiation. Recruitment of the small ribosomal subunit can indeed be modulated by mRNA secondary structure, antisense RNA binding, or protein binding. In both prokaryotes and eukaryotes, a large number of RNA binding proteins exist, which often are directed to their target sequence by the secondary structure of the transcript, which may change depending on certain conditions, such as temperature or presence of a ligand (aptamer). Some transcripts act as ribozymes and self-regulate their expression.
New types of flavored and/or nutrient-added water beverages have begun to appear in stores and on food service menus. Some are simply bottled water with flavoring, others may also contain added nutrients such as vitamins, electrolytes like sodium and potassium, and amino acids. The bottled water ingredients of these flavored and nutrient-added water beverages must meet the bottled water requirements if the term "water" is highlighted on the label as in, for example, a product named Berry Flavored Spring Water Beverage . In addition, the flavorings and nutrients added to these beverages must comply with all applicable FDA safety requirements and they must be identified in the ingredient list on the label.