Medicine Medical SuppliesDetection Kit
Chromogranin A (ChgA) is also called parathyroid secretory protein 1, consists of 439 amino acids that is a 49 kDa acidic protein encoded on chromosome 14. It belongs to the member of granin family of neuroendocrine secretory proteins and has been identified in a large number of normal and neoplastic endocrine tissues. Examples of cells that are producing chromogranin A include chromaffin cells of the medulla, adrenal, enterochromaffin-like, paraganglia and beta cells of the pancreas. They are present in the islet beta cell secretory granules. It is a precursor to several functional peptides such as pancreastatin, vasostatin-1, vasostatin-2, parastatin and catestatin, all of these peptides have the ability to negatively modulate the neuroendocrine function nearby cells (paracrine response) or releasing cell (autocrine response). Chromogranin A has the ability to induce and promote the generation of secretory granules such as those containing insulin within pancreatic islet beta cells.
There have been evidence to suggest that elevated circulating chromogranin A levels would be vital markers for tumors of neuroendocrine origin. However, recently, one of the most significant clinical use of chromogranin A has been related to the diagnostic procedure in patients of pheochromocytoma. It was found that the drugs that were often used to treat and diagnose pheochromocytoma had very little effect on the plasma concentrations of chromogranin A. This finding meant that measuring chromogranin A instead of catecholamines would offer greater advantages. It therefore provides a very sensitive and highly specific marker in the evaluation of suspected or actual pheochromocytoma patients.