Disease relevance of Endolymphatic Sac

• Vasopressin hypersensitivity of the endolymphatic sac may be implicated in the pathogenesis of Meniere's disease [1].
• The authors report a case of endolymphatic sac tumor (ELST) associated with Von Hippel-Lindau disease (VHL) [2].
• Tumors can also invade the CPA by extension from the petrous bone or skull base (cholesterol granuloma, paraganglioma, chondromatous tumors, chordoma, endolymphatic sac tumor, pituitary adenoma, apex petrositis) [3].
• Intratympanic gentamicin therapy for persistent vertigo after endolymphatic sac surgery [4].
• Acetazolamide as well as amiloride caused collapse of the lateral intercellular spaces in the endolymphatic sac epithelium and a subsequent mild endolymphatic hydrops [5].

High impact information on Endolymphatic Sac

• Patients with ATP6B1 mutations also have sensorineural hearing loss; consistent with this finding, we demonstrate expression of ATP6B1 in cochlea and endolymphatic sac [6].
• Inactivation of the wild-type copy of the VHL gene leads to up-regulation of hypoxic response and tumor formation within central nervous system (CNS), kidneys, pancreas, adrenal glands, epididymis, broad ligament, and the endolymphatic sac/petrous bone [7].
• Six1-deficient embryos were devoid of inner ear structures, including cochlea and vestibule, while their endolymphatic sac was enlarged [8].
• Dlx3 expression then resolves to the dorsal otocyst and gradually becomes limited to the endolymphatic sac by stage 30 [9].
• We detected mRNA for the three channel-forming subunits (alpha, beta and gamma ENaC) in cochlea, vestibular system and endolymphatic sac. mRNA abundance increased during the first 12 days of life in cochlea and vestibular system, coinciding with decreasing Na(+) concentration in endolymph [10].

Chemical compound and disease context of Endolymphatic Sac

• This study, using mice, correlated serum osmotic pressure, experimentally elevated with an intravenous injection of glycerol of varying tonicity (1.3, 2.6 and 5.2 g glycerol/kg body weight) with endolymphatic sac (ES) response [11].
• PATIENTS: 112 patients with Méniére's disease, who had undergone endolymphatic sac surgery or intratympanic gentamicin injections, or were surgically untreated [12].
• The morphological changes of the inner ear were observed after intravenous administration of 2 g/kg of urea to the guinea pigs with endolymphatic hydrops which had previously been produced by injecting 10% silver nitrate solution into the endolymphatic sac [13].
• Three basic pathologic mechanisms have emerged: fibrosis of the endolymphatic sac and vestibular epithelia, altered glycoprotein metabolism, and inner ear viral infection [14].
• In this study, we investigated the rebound phenomenon occurring with isosorbide, an osmotic diuretic used as a therapeutic agent for Ménière's disease in Japan. Forty guinea pigs underwent surgical obliteration of the endolymphatic sac [15].

Biological context of Endolymphatic Sac

• The endolymphatic sac and inner ear homeostasis. II: Effect of glycerol on the sensory end organs with or without colchicine pretreatment [16].
• Effects of acetazolamide on acid-base balance in the endolymphatic sac of the guinea pig [17].
• Calmodulin binding sites in the endolymphatic sac and stria vascularis of the human fetus and the guinea pig [18].

Anatomical context of Endolymphatic Sac

• The authors present a case of endolymphatic sac tumor, a rare adenomatous tumor of the temporal bone, in a patient with von Hippel-Lindau (VHL) disease [19].
• The endolymphatic sac contains aragonite crystals while the saccule contains calcite crystals adjacent to the wall, in addition to a preponderance of aragonite crystals [20].
• The fine structure and its functional properties of both free floating cells and epithelial cells in the endolymphatic sac after injections of India ink particles or polystyrene latex beads, 0.24 micron in diameter, into the endolymphatic space, were studied using light and electron microscopy [21].
• If this is true, the hyalin bodies may further support the proposed resorptive and phagocytic functions of the endolymphatic sac and the enzymatic concept in cochlear otosclerosis [22].
• It is concluded that the cells in the endolymphatic sac lumen contribute to the amplification of the adaptive immune response by expressing TNFalpha, while the infiltration of cells into the perisaccular connective tissue is part of the nonspecific, innate, cochlear immune response [23].

Associations of Endolymphatic Sac with chemical compounds

• The levels of AQP2 mRNA in the cochlea and endolymphatic sac were significantly higher in rats treated with vasopressin than the levels in control animals [24].
• The exact contribution of the entire endolymphatic sac system to lactate buffering could not be determined in the present study [25].
• The combined effects of glycerol and colchicine on the endolymphatic sac were investigated in mice [26].
• Quantitative analysis of physiologic measurements from the endolymphatic sac requires knowledge of the anatomy of the structure, specifically the luminal volume and the variation of cross-sectional area with distance along the sac [27].
• Within 15 min after administration of glycerol and urea the lumen of the endolymphatic sac was partially collapsed and the density of its contents was increased [28].

Gene context of Endolymphatic Sac

• Delta1 is also expressed: (a) at early stages, at the site of otic neurogenesis; and (b) in scattered cells of the endolymphatic sac, as is Serrate1 [29].
• Expression of carbonic anhydrase isoenzymes in the developing endolymphatic sac of the human fetus and the mouse embryo [30].
• Coexpression of erythropoietin and its receptor in endolymphatic sac tumors [31].
• The postnatal appearance of aquaporin 2 transcripts in the endolymphatic sac resembled that in the kidney, i.e. it increased postnatally until day 4 [32].
• On the other hand, TNFalpha, which plays an important role in the cochlear secondary immune response, was expressed in cells in the endolymphatic sac lumen [23].

Analytical, diagnostic and therapeutic context of Endolymphatic Sac

• Fifteen minutes after intravenous injection of urea or glycerol, subcellular changes in the endolymphatic sac were observed [33].
• The cochleas and endolymphatic sacs were assayed by immunocytochemistry for IL-1beta, TNFalpha, and IL-6 [23].
• The endolymphatic sac was studied after daily intraperitoneal injection of 75 mg/kg kanamycin for 10 and 20 days to see whether or not the endolymphatic sac showed signs of increased phagocytic activity [34].
• The effects of acetazolamide, a carbonic anhydrase inhibitor, on acid-base parameters in the endolymphatic sac of the guinea pig were investigated using ion-selective microelectrodes [17].
• Scanning electron microscopy and immunoglobulins of the endolymphatic sac in normal human subjects and sensorineural deafness. With special reference to Menière's disease [35].

References