[Immunoreactive parathyroid hormone in samples from thyroid veins (author's transl)].

Blood samples were obtained from 16 patients with primary or secondary hyperparathyroidism by selectively catheterising cervical and thyroid veins. Immunoreactive parathyroid hormone was measured with two aminoterminal (anti-N)- and three carboxyl-terminal (anti-C)-specific antisera. Two anti-C sera and one anti-N serum were useful in localising the parathyroid tumors. In addition, the parathyroid hormone fragments were separated by gelfiltration and the immunoreactivity in the effluent was estimated with anti-N and anti-C sera. The results suggest that the usefulness of antisera for parathyroid tissue localisation is determined by their affinity for the intact hormone, regardless of their anti-N or anti-C qualities.