Endolymph

Endolymph is the specialized extracellular fluid contained within the membranous labyrinth of the inner ear, specifically the cochlear duct and the vestibular organs [1][3]. It is unique among extracellular fluids due to its high potassium (K+) and low sodium (Na+) concentration, a composition maintained by the stria vascularis that is essential for generating the endocochlear potential required for hair cell depolarization [1]. While endolymph is a physiological fluid compartment rather than a specific molecular target like a receptor or enzyme, its regulation is central to auditory and vestibular health [2]. Pathological expansion of the endolymphatic space, known as endolymphatic hydrops, is the primary histological finding in Meniere's disease, leading to episodic vertigo, tinnitus, and progressive hearing loss [2][4]. Pharmacological management typically involves the use of diuretics and osmotic agents to reduce endolymphatic pressure and volume, thereby alleviating clinical symptoms [2][4]. (Sources: [1] StatPearls: Physiology, Inner Ear; [2] StatPearls: Meniere Disease; [3] Britannica: Endolymph; [4] MSD Manual: Meniere Disease)

Other names

Scarpa's fluidEndolymphatic fluid

Reduction of endolymphatic volume and pressure via osmotic dehydration or inhibition of carbonic anhydrase-mediated fluid production; modulation of microvascular circulation to the stria vascularis.