Adenosine receptors as drug targets

Area of Science:

• Pharmacology
• Molecular Biology
• Physiology

Background:

• Four adenosine receptors (A1, A2A, A2B, A3) form a G protein-coupled receptor subgroup.
• These receptors are highly conserved and widely expressed throughout the body.
• The endogenous agonist, adenosine, is present at low physiological concentrations (20-200 nM).

Purpose of the Study:

• To explore the physiological and pathophysiological roles of adenosine receptors.
• To identify potential drug targets related to adenosine receptor function.
• To understand the complexities in developing drugs targeting adenosine receptors.

Main Methods:

• Review of existing literature on adenosine receptor function.
• Analysis of adenosine's physiological and stress-induced concentrations.
• Examination of adenosine receptor involvement in various biological processes.

Main Results:

• Adenosine receptors are activated at sites of high expression, such as the basal ganglia, fat cells, and kidneys.
• Adenosine levels increase significantly during stress and ischemia (up to 30 microM).
• Adenosine mediates protective effects during stress, including increased energy supply and immune cell modulation.

Conclusions:

• Adenosine receptors have critical physiological roles and are involved in stress responses.
• The diverse functions of adenosine receptors present challenges for drug development.
• Understanding adenosine receptor pathways offers potential therapeutic strategies but requires careful consideration of off-target effects.