Regulation of anterior pituitary D2 dopamine receptors by magnesium and sodium ions

J Neurochem. 1985 Dec;45(6):1842-9. doi: 10.1111/j.1471-4159.1985.tb10542.x.

Abstract

At D2 3,4-dihydroxyphenylethylamine (dopamine) receptors in anterior pituitary tissue, magnesium ions shifted receptors to agonist high-affinity states, but decreased the affinity of the antagonist [3H]spiperone. Conversely, sodium ions shifted the receptors to agonist low-affinity states, but increased the affinity of [3H]spiperone. Magnesium is proposed to stabilize the hormone-receptor-guanine nucleotide regulatory protein complex, whereas sodium appears to destabilize this ternary complex. Thus, magnesium and sodium appear to mediate their regulatory effects via a common component at the D2 dopamine-receptor ternary complex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apomorphine / analogs & derivatives
  • Apomorphine / metabolism
  • Dopamine / metabolism
  • Guanine Nucleotides / metabolism
  • Magnesium / pharmacology*
  • Pituitary Gland, Anterior / drug effects*
  • Pituitary Gland, Anterior / metabolism
  • Receptors, Dopamine / drug effects*
  • Receptors, Dopamine / metabolism
  • Receptors, Dopamine D2
  • Sodium / pharmacology*
  • Spiperone / metabolism
  • Swine

Substances

  • Guanine Nucleotides
  • Receptors, Dopamine
  • Receptors, Dopamine D2
  • Spiperone
  • N-n-propylnorapomorphine
  • Sodium
  • Magnesium
  • Apomorphine
  • Dopamine