Dopamine D1 receptors in human parathyroid gland: in vitro and in vivo studies.

Dopamine receptors in human parathyroid were studied in vitro using ligand binding techniques. With 3H-piflutixol as ligand, binding characteristic of the dopamine D1 receptor was observed. Administration of apomorphine, flupenthixol or metoclopramide to normal controls or acute schizophrenic patients at doses producing significant alterations in serum prolactin concentrations did not alter serum parathyroid hormone (PTH) concentrations. Whilst D1 binding sites are present in human parathyroid, the measurement of PTH after administration of dopaminergic drugs is unlikely to provide a test of D1 receptor function in man.