agonisme en antagonisme

• -       Agonist = Activates a receptor

  o   Like the effect of an endogenous substance

  -       Antagonist = Inhibits a receptor

  o   Blocks the effect of the agonist by binding to the same receptor

  o   Either lower occupancy or number of available receptors

  o   Have no intrinsic efficacy
• o   ompetitive antagonism:

  • Right shift in dose response curve, the amount of right shift depends on the amount of antagonists
  • You can still reach the maximum occupancy as long as you keep adding agonists
  • Reversible antagonist

  o   Non-competitive antagonism:

  • Block of function
  • Irreversible antagonist
  • Lower the maximal concentration of bound ligand
  • Isn’t permanent, because receptors are proteins and proteins have a short half life
• o   You can prove agonists with antagonists
• Agonists or antagonists that bind covalently never let go