granuleinhoud

Granuleinhoud refers to the molecular composition and content stored within cellular granules, which are membrane-bound vesicles found in various cell types, notably in hematopoietic and secretory cells. Granules function as storage depots for proteins, enzymes, small molecules and signaling mediators that can be rapidly released upon stimulation. The specifics depend on the cell type. For example, platelets contain alpha granules with fibrinogen, von Willebrand factor and other adhesion molecules, and dense granules with ADP, calcium and serotonin. Neutrophils have azurophilic granules rich in myeloperoxidase and hydrolases, and specific granules containing lactoferrin and gelatinase; mast cells store histamine, heparin and proteases. In cytotoxic lymphocytes, granules carry perforin and granzymes to kill target cells.

The study of granuleinhoud involves methods such as subcellular fractionation, electron microscopy to assess granule size and density, and proteomic or biochemical analyses to identify contained proteins and mediators. Functionally, granuleinhoud determines the rapidity and nature of the secretory response, and changes in granuleinhoud accompany cell maturation, activation or disease. Abnormal granuleinhoud is involved in disorders such as storage pool deficiencies in platelets and Hermansky-Pudlak or Chediak-Higashi syndromes, which affect granule biogenesis and storage. Variation across species and cell types means granuleinhoud is a context-dependent property used in physiology, hematology and immunology.