Adrenal medullary calcitonin-like factor: a key to multiple endocrine neoplasia, type 2?

An adrenal calcitonin-like extract, previously demonstrated to be indistinguishable from porcine thyroid calcitonin by bio- and radioimmunoassay has now been localized to the adrenal medulla of the pig. An equal weight of adrenal medulla contains from 7 to 28 percent as much calcitonin-like activity as does thyroid from the same animals. These findings support the hypotheses that C cells, which produce calcitonin, are of neuralcrest origin and that extrathyroidal calcitonin may be of considerable importance in some species. Finally, these results suggest that the syndrome of medullary carcinoma of the thyroid gland, pheochromocytomas, and multiple neuromas may be a systemic disorder of neuroectodermal cells.