Expression of Chromogranin-A Messenger Ribonucleic Acid in Parathyroid Tissue from Patients with Primary Hyperparathyroidism

Chromogranin-A (CgA), also termed secretory protein-I, is an acidic glycoprotein that is synthesized and secreted by cells of the diffuse endocrine and neuroendocrine system. Several previous studies had suggested that plasma levels of CgA were elevated in patients with primary hyperparathyroidism. In the present study we sought to examine expression of the CgA gene in human parathyroid tissue from patients with primary hyperparathyroidism. We characterized the mRNAs coding for CgA and β-actin in parathyroid tissue fragments obtained from 12 patients with parathyroid adenomas, 11 patients with familial multiple endocrine neoplasia type I (FMEN I) with parathyroid hyperplasia, and 11 normal subjects. The mRNAs were detected and analyzed by dot and Northern blot hybridization using cDNA probes. CgA mRNA transcripts of 2.1 kilobases were detected in normal and pathological parathyroids. Similarly, β-actin mRNA species of 2.1 kilobases was present in all tissues. The relative level of parathyroid tissue CgA m...