Physicochemical buffering of systemic and urinary pH

Physicochemical buffering of systemic and urinary pH is a fundamental physiological mechanism rather than a single molecular target, encompassing the coordinated action of chemical buffers, respiratory gas exchange, and renal ion transport (StatPearls, 2023). The primary systemic buffer is the bicarbonate-carbonic acid system, which works in tandem with intracellular proteins and phosphate to maintain arterial pH between 7.35 and 7.45 (Merck Manual, 2022). In the renal system, buffering is achieved through the excretion of ammonium ions and titratable acids, which prevents the urine from becoming excessively acidic and allows for the continued elimination of metabolic waste (CJASN, 2015). While not a protein target, this process is pharmacologically modulated using alkalinizing agents like sodium bicarbonate or potassium citrate to manage metabolic acidosis and prevent the formation of certain kidney stones (NIH, 2023). Conversely, carbonic anhydrase inhibitors like acetazolamide are used to manipulate this system for conditions such as glaucoma or altitude sickness by altering bicarbonate reabsorption (StatPearls, 2023). Understanding these buffering dynamics is crucial for managing acid-base disturbances in critically ill patients and optimizing the pharmacokinetics of drugs whose excretion is pH-dependent (PubChem, 2024).

Other names

Acid-base homeostasispH regulationBicarbonate-carbonic acid buffering systemUrinary acidificationSystemic pH buffering

Modulation of the concentration of hydrogen and bicarbonate ions through exogenous supplementation, enzymatic inhibition, or alteration of renal ion transport.