1989 Volume 52 Issue Supplement Pages 99-105
Two novel monoclonal antibodies, called B11 and B13, directed exclusively against human chromogranin B (CgB) and another antibody, All, specific for human chromogranin A (CgA), were obtained by immunization of mice with chromaffin granules, the fission of their splenocytes, the screening of hybridomas supernatants by ELISA and immunohistochemistry, and characterization of the antibodies by two-dimensional immunoblotting.
The antibodies were used in immunohistochemical tests to investigate the distribution of CgA and CgB in hormonally-identified cells of the human endocrine system. The All antibody confirmed the occurrence of CgA in gut EC, ECL, gastrin, secretin and neurotensin cells, pancreatic A and PP cells, parathyroid chief cells, pituitary TSH and gonadotrope cells and adrenal medullary cells. Only a fraction of CgA-immunoreactive cells in the human gut and pancreas showed C-terminus arginineglycinamide immunoreactivity, suggesting pancreastatin storage. Both CgB antibodies showed immunoreactivity in gastrin cells, intestinal (but not gastric) EC cells, pancreatic A and PP cells, pituitary TSH and gonadotrope cells and adrenal medullary cells. In addition, the B11 antibody stained thyroid C cells and the B13 antibody stained the Golgi area of pituitary GH cells. It is concluded that most CgB is stored in the same cells showing CgA, although some CgA-rich cells, like gastric EC and ECL cells, lacked B11 and B13 immunoreactivities and some CgA-poor cells, like human thyroid C cells, showed intense B11 immunostaining.
