PD-123319 is primarily utilized in research settings as a selective antagonist for the angiotensin II type 2 (AT2) receptor. It is commonly employed in studies aimed at understanding the physiological and pathological roles of the AT2 receptor in various systems, including the cardiovascular and renal systems. By blocking the AT2 receptor, PD-123319 helps researchers investigate its involvement in processes such as blood pressure regulation, tissue repair, and inflammation. This compound is particularly valuable in differentiating the effects of AT2 receptor signaling from those mediated by the angiotensin II type 1 (AT1) receptor, providing insights into the complex mechanisms of the renin-angiotensin system.