Inhibition of inositol phospholipid breakdown by D2 dopamine receptors in dissociated bovine anterior pituitary cells.

Inositol phospholipids have been labelled with [3H]inositol in a lactotroph-enriched preparation of dissociated bovine anterior pituitary cells. Stimulation of cells with thyrotropin-releasing hormone receptor agonists leads to accumulation of [3H]inositol phosphates, and this effect may be inhibited by dopamine (DA) agonists. The DA agonist effect may be prevented by D2 DA receptor selective antagonists. Thus the D2 receptors on these cells are linked to inhibition of inositol phospholipid metabolism, and this provides a functional assay for the receptor.