Dopamine does not affect parathyroid function in man

There is conflicting evidence for a role of dopamine (DA) in modulating parathyroid gland function. DA stimulates parathormone (PTH) secretion in cattle in vivo and in vitro, but is without effect on dispersed human parathyroid cells from adenomatous and hyperplastic tissue. Therefore, we studied the PTH response to a 30-min infusion of DA (4 micrograms/kg . min) in five normal male volunteers. There was no change in the levels of PTH, as measured by RIA, although this infusion rate was effective in lowering PRL levels. During the infusion period, total calcium levels remained unchanged. We conclude that, unlike cattle, the parathyroid gland in humans is unresponsive to DA. Thus, the regulation of PTH secretion by biogenic amines has important species variation.