The evolution of assays for parathyroid hormone.

Recent progress in the assay of parathyroid hormone has revealed that commercially available assays for intact parathyroid hormone also measure additional parathyroid hormone peptides that appear to be truncated at the amino-terminal region and have the elution position on high-performance liquid chromatography of parathyroid hormone 7-84. Specific assays have been developed that measure only the true or 'whole', 84-amino-acid peptide. Such 'whole' parathyroid hormone assays have led to the discovery of new findings that suggest that parathyroid hormone fragments such as parathyroid hormone 7-84, which have hitherto been considered to be biologically inactive, may actually have biologic effects. These data, coupled with the emerging discovery of additional receptors for parathyroid hormone peptides, suggest that parathyroid hormone fragments might have potentially important actions, at least in the setting of renal failure.