Читать книгу Neurobiology For Dummies - Frank Amthor - Страница 76

Osmotic imbalances are detected by a variety of sensors in cells, which respond in many ways such as with secretion, enzyme production, or changes in gene expression. Mechanosensitive channels in cell membranes respond to mechanical stress such as stretching of the membrane. These channels open or close to allow bulk flow of ions through the membrane to balance between different concentrations inside versus outside. Protein pump molecules may selectively bring in or expel soluble ions in response to different total ionic concentrations inside versus outside the cell.

A recently discovered channel family termed TRPV (short for transient receptor potential vanilloid ) responds to osmotic stress by allowing calcium influx. The increased calcium concentration inside the cell regulates volume by activating calcium-dependent potassium channels. Defective TRPV channels are associated with cystic fibrosis.