Renal plasma flow (RPF)

Renal plasma flow (RPF) is a fundamental physiological parameter that quantifies the volume of blood plasma delivered to the kidneys per unit of time, typically representing approximately 20% of the total cardiac output [1, 7, 13]. It is a critical determinant of the glomerular filtration rate (GFR) and is essential for the kidney's primary functions, including the excretion of metabolic waste, maintenance of fluid and electrolyte balance, and regulation of systemic blood pressure [1, 14]. While RPF is not a molecular target such as a receptor or enzyme, it serves as a vital clinical endpoint and a measure of renal perfusion that is significantly influenced by various pharmacological agents [3, 6]. Drugs such as ACE inhibitors, angiotensin II receptor blockers (ARBs), and nonsteroidal anti-inflammatory drugs (NSAIDs) modulate RPF by altering the vascular resistance of the afferent and efferent arterioles [5, 10]. Clinically, RPF is often estimated using the clearance of para-aminohippuric acid (PAH), which is almost entirely secreted by the renal tubules, or through advanced imaging techniques like BOLD-MRI to assess renal health in conditions such as hypertension, heart failure, and chronic kidney disease [8, 11, 15]. Maintaining adequate RPF is crucial for preventing acute kidney injury and ensuring long-term renal stability [5, 8].

Other names

RPFEffective renal plasma flowERPFTrue renal plasma flowTRPFRenal perfusion

Pharmacological agents modulate renal plasma flow by altering the vascular resistance of the afferent and efferent arterioles. For instance, ACE inhibitors and ARBs decrease efferent arteriolar resistance by blocking the effects of angiotensin II, whereas NSAIDs can decrease RPF by inhibiting the synthesis of vasodilatory prostaglandins that maintain afferent arteriolar patency [1, 5, 6].