Acid-base homeostasis system

Acid-base homeostasis is the physiological process of maintaining the tight regulation of hydrogen ion concentration (pH) in the extracellular fluid, primarily through the coordinated actions of the lungs, kidneys, and chemical buffer systems (StatPearls, 2023). The lungs manage the excretion of volatile acid (CO2), while the kidneys regulate the excretion of non-volatile acids and the reabsorption of bicarbonate (Merck Manual, 2022). Dysregulation of this system leads to clinical conditions such as acidosis or alkalosis, which can impair cellular function, enzyme activity, and cardiac stability (PubMed, 2021). While the system itself is not a single molecular target, specific components within it—such as carbonic anhydrases and various ion transporters like NBCe1 (SLC4A4) or NHE3 (SLC9A3)—are targeted by pharmacological agents to treat glaucoma, edema, and chronic kidney disease-related acidosis (NIH, 2023). Drugs interacting with this system often aim to modulate the net acid-base load or the rate of ion exchange across biological membranes to restore physiological pH.

Other names

pH regulationAcid-base balanceAcid-base physiology

Pharmacological agents targeting this system typically act by inhibiting carbonic anhydrase enzymes to decrease bicarbonate reabsorption, providing exogenous alkaline buffers to neutralize metabolic acids, or utilizing intestinal binders to remove hydrochloric acid from the body.