Vasoactive intestinal polypeptide-, neurotensin-, substance P-, gastrin-releasing peptide-, calcitonin-, calcitonin gene related peptide-, and somatostatin-like immunoreactivities in human parathyroid glands.

We have found vasoactive intestinal polypeptide (VIP)-, neurotensin-, substance P-, gastrin-releasing peptide-, calcitonin-, calcitonin gene related peptide (CGRP-2)-, and somatostatin-like immunoreactivities in extracts of sporadic human parathyroid adenomas (n = 18). The content of CGRP-2, substance P, and somatostatin in adenomas correlated directly with that of parathyroid hormone. In addition, concentrations of VIP versus substance P and somatostatin versus CGRP-2 in adenomas were directly correlated. Neuropeptide content of parathyroid hyperplasias differed from that of adenomas. VIP was detected in only one of seven parathyroid hyperplasias, and neurotensin was undetectable (0/7), whereas substance P was present in six of seven cases and GRP in five of seven hyperplasias. In hyperplasias, content of substance P correlated directly with that of gastrin-releasing peptide. Peroxidase immunohistochemistry localized VIP-like immunoreactivity to 20% to 50% of both chief and oxyphilic cells and rare clear cells and capillary endothelium in 11 of 12 adenomas studied. Focal staining was present in glandular epithelium of the rim of adjacent normal parathyroid tissue and in two of three normal parathyroid glands removed with thyroid goiters. This staining was both cytoplasmic and apical membrane. By contrast, in adenomas, neurotensin- and substance P-like positivities were confined to scattered (5% to 10%) oxyphilic cells. Cytoplasmic positivity for parathyroid hormone, noted in 30% to 70% of cells in serial sections, confirmed that these tissues were indeed parathyroid glands.