Characterisation using microphysiometry of CRF receptor pharmacology

Area of Science:

• Pharmacology
• Receptor Biology
• Biophysics

Background:

• Corticotropin-releasing factor (CRF) receptors are crucial in regulating stress responses.
• Understanding CRF receptor pharmacology is vital for developing targeted therapeutics.
• Existing methods for studying receptor activity can be limited in scope or throughput.

Purpose of the Study:

• To evaluate the Cytosensor microphysiometer for studying recombinant human CRF receptor pharmacology.
• To characterize the activity of various CRF receptor agonists and antagonists using this system.
• To confirm the Cytosensor's viability for functional assessment of CRF receptor ligands.

Main Methods:

• Chinese hamster ovary cells expressing human CRF1 or CRF2 receptors were utilized.
• Cells were perfused in a Cytosensor microphysiometer with a specialized Hams F12 medium.
• Agonist potency and antagonist affinity were determined through microphysiometry measurements.

Main Results:

• Distinct rank orders of agonist potency were observed for CRF1 (CRF=sauvagine=urocortin=urotensin) and CRF2 (urocortin>sauvagine>urotensin>CRF) receptors.
• alpha-Helical CRF (9-41) acted as a competitive antagonist at CRF2 and a partial agonist at CRF1.
• CP 154,526 demonstrated competitive antagonism at CRF1 but was inactive at CRF2.

Conclusions:

• The Cytosensor microphysiometer is a viable and effective tool for assessing CRF receptor pharmacology.
• The observed pharmacological profiles align with established knowledge of CRF receptor function.
• This method provides a robust platform for functional screening of CRF receptor modulators.