Abstract
BACKGROUND AND PURPOSE: The human P2X7 (hP2X7) receptor exhibits striking pharmacological differences from its rodent counterparts, particularly in terms of its antagonist profile. Here, we characterized the functional and pharmacological properties of the rhesus macaque monkey P2X7 (rmP2X7) receptor in comparison with the hP2X7 receptor. EXPERIMENTAL APPROACH: The rmP2X7 and hP2X7 receptors were heterologously expressed in HEK293 cells. The receptor surface and total expression levels were examined by biotin-labelling and Western blotting. The functional and pharmacological properties were characterized using patch-clamp recording and single-cell imaging. KEY RESULTS: The rmP2X7 receptor showed strong cell surface expression. Both ATP and 2'(3')-O-(4-benzoylbenzoyl) adenosine-5'-triphosphate (BzATP) were full agonists in activating the rmP2X7 receptor; the EC₅₀ values were 802 µM for ATP and 58 µM for BzATP, respectively, in extracellular low divalent cation solution. Prolonged activation of the rmP2X7 receptors induced detectable but low level YO-PRO-1 uptake. KN-62, AZ11645373 and A-438079, three hP2X7 selective antagonists, all potently inhibited the rmP2X7 receptor-mediated currents; the IC₅₀ values were 86, 23 and 297 nM respectively. CONCLUSION AND IMPLICATIONS: The rmP2X7 receptor exhibits similar pharmacological properties to the hP2X7 receptor. The rhesus macaque monkey thus may represent a valuable model species in elucidating the mechanisms and pharmacological interventions of hP2X7 receptor-related diseases.