granins

granins

A family of acidic, soluble secretory proteins that include various chromogranins and secretogranins. The granins occur in vesicles in neurons and neuroendocrine cells. They are prohormones and give rise to bioactive peptides and can be used as markers of sympathoadrenal activity and of secretion from normal and neoplastic neuroendocrine cells into the bloodstream. Some granins are sensitive markers. Raised levels of chromogranin A, for instance, may allow confident diagnosis of PHAEOCHROMOCYTOMA, VON HIPPEL-LINDAU DISEASE or NEUROFIBROMATOSIS.