Beta-adrenergic binding is increased by melatonin and alpha-adrenergic compounds.

Academic Article


  • Binding of the beta-adrenergic ligands [3H]dihydroalprenolol and [125I]cyanopindolol to pineal particulate fractions was increased 1- to 3.5-fold by addition of low concentrations of melatonin, alpha-adrenergic agonists, or alpha-adrenergic antagonists. Minimum concentrations of melatonin or alpha-adrenergic compounds which increased beta-adrenergic binding were between 1 pM and 0.1 nM. The increased binding of [3H]dihydroalprenolol caused by melatonin (0.1 muM) was attributed to a major increase in Bmax, which persisted in protein fractions after removal of melatonin. Melatonin enhancement of [3H]dihydroalprenolol binding was apparent after 5 to 7 min (30(0], was was optimal between 20 and 40 min, and decreased at longer times. Alpha-Adrenergic receptors are unchanged during beta-receptor enhancement.
  • Keywords

  • Adrenergic alpha-Agonists, Adrenergic alpha-Antagonists, Animals, Dihydroalprenolol, Iodocyanopindolol, Kinetics, Melatonin, Pindolol, Pineal Gland, Rabbits, Receptors, Adrenergic, beta
  • Author List

  • Sweat FW; Gower BA; Berger PG; Negus NC
  • Start Page

  • 1196
  • End Page

  • 1202
  • Volume

  • 138
  • Issue

  • 3