Functional Autoradiography [35S]-GTPγS

[35S]-GTPγS receptor binding is used to study the distribution and functional activation of neurotransmitter receptors (GPCRs) in tissue sections (rodent, non-human primate & human). This technique combines the advantages of receptor autoradiography and [35S]-GTPγS binding, providing anatomical and functional (EC50 & EMAX) information. Upon binding of an agonist, activated GPCRs can be visualized in the sample.

Functional Receptor Autoradiography can be used to:

  • Determine the pharmacological values of potency (EC50) & efficacy (EMAX) of the ligand to activate the GPCR of interest
  • Visualize regional differences of activated GPCRs by a ligand
  • Determine if the ligand is an agonist or antagonist
Autoradiograph of Basal & Agonist stimulated 35S-GTPgammS binding in rodent brain tissue (whole brain).
Both 8-OH-DPAT (1uM) and 5-HT (1uM) stimulated 35S-GTPgammaS binding in human hippocampal membrane preparation. Pindolol (10uM), a potent 5-HT1A receptor antagonist, blocked 8-OH-DPAT–stimulated 35S-GTPgammaS binding.
Autoradiograph of Basal, Non-specific (NSB) & Agonist stimulated 35S-GTPgammS binding in human tissue (cortex).