Systemic fluid, electrolyte, and acid–base homeostasis

Systemic fluid, electrolyte, and acid–base homeostasis is the physiological process by which the body maintains the volume, composition, and pH of extracellular and intracellular fluids. This regulation is essential for cellular function, nerve conduction, and enzymatic activity, and is primarily managed by the kidneys, lungs, and endocrine system (StatPearls, 2023). The kidneys regulate the excretion of water and electrolytes like sodium and potassium, while the lungs control carbon dioxide levels to manage blood pH (NIH, 2022). Disruptions in these balances result in clinical conditions such as metabolic acidosis, hyponatremia, or hyperkalemia, which can lead to life-threatening complications like cardiac arrest or seizures. While this is a physiological state rather than a single molecular target, it is the functional objective of numerous therapeutic interventions. Pharmacological agents such as diuretics, ACE inhibitors, and mineralocorticoid receptor antagonists exert their effects by modulating specific molecular pathways within this broader homeostatic framework (PubMed, 2021). These drugs target specific transporters and receptors to restore equilibrium in patients with hypertension, heart failure, or renal disease.

Other names

Acid-base balanceFluid and electrolyte balanceInternal milieu regulationHomeostatic regulation of body fluids

Pharmacological agents modulate this physiological state by targeting specific molecular components such as ion transporters (e.g., NKCC2), enzymes (e.g., carbonic anhydrase), or receptors (e.g., V2 vasopressin receptor) to alter the excretion or retention of water and solutes (PubMed, 2021).