What does SU mean in BRITISH MEDICINE

The secretory unit (SU) is an organelle involved in the secretion of proteins and other molecules out of the cell into extracellular spaces or other cells. It consists of the cisternae of rough endoplasmic reticulum connected to Golgi Apparatus by vesicle transport systems.

The proteins or molecules that need to be secreted are synthesized on the rough endoplasmic reticulum (RER) and then transported via vesicles to the Golgi apparatus for further processing and packaging, before being secreted from the cell by way of exocytosis.

Exocytosis is a process where a membrane-bound vesicle containing macromolecules fuses with the plasma membrane allowing its contents to leave, or be transported outside, of the cell. This process usually occurs at specific locations on the outside surface or inbetween cells depending on what needs to be secreted.

Some examples include hormones such as thyroid hormones, glucose hormones like insulin and glucagon, cytokines like interferons, and signaling molecules such as neurotransmitters.

When there is dysfunction in the secretory unit, abnormal levels of these compounds may be produced leading to a wide range of medical conditions. For example, diabetes can occur due to malfunctioning SUs responsible for secreting insulin and glucagon hormones which control blood sugar levels.